Hi all,
i am just overwhelmed after seeing this thread..almost tears in my eyes.
It's indeed great place for people who working on their own, so it's for me!!
Three things All question posting people should take care of are:
1. Specify the Chapter in Heading of Post itself.
2. In Question body specify the question No and LOD I/II/III
3. then write whole question body itself fully word by word as in book.
Additioanlly Whole Solution to perticular question should be given by Clicking on Quote. So it will be easy for people who just landed directly to this scrap.
Thanks
qn: Vinay fires two bullets from the same place at an interval of 12 mins but shyam who is on a train approaching vinay hears the seacond after an interval of 11 min 30s. speed of sound =330m/s. Find the speed of train.
ans:1. 660/23 2. 220/7 3. 330/23 4. 110/23.
I am getting the answer as (3) 330/23 (although by a pretty long method), so if the answer is correct then i can post the solution, otherwise there is no point typing my heart out explaining a wrong answer.So, please tell me whether this answer is correct or not
Q.1 Find two-three digit numbers whose sum is multiple of 504 and the quotient is a multiple of 6.
Q.2 There is a natural number that becomes equal to the square of a natural number when 100 is added to it,and to the square of another natural number when 169 is added to it . Find the number?
Q.3 The sum of the cubes of the digits constituting a two digit number is 243 and the product of the sum of its digits by the product of its digits is 162. Find the two digit number.
(No option)(Plz explain the ans after solving)
Q.2 There is a natural number that becomes equal to the square of a natural number when 100 is added to it,and to the square of another natural number when 169 is added to it . Find the number?
Q.3 The sum of the cubes of the digits constituting a two digit number is 243 and the product of the sum of its digits by the product of its digits is 162. Find the two digit number.
(No option)(Plz explain the ans after solving)
Q.3 The sum of the cubes of the digits constituting a two digit number is 243 and the product of the sum of its digits by the product of its digits is 162. Find the two digit number.
(No option)(Plz explain the ans after solving)
Use the formula:
(a + b)^3 = a^3 + b^3 + 3ab*(a+b)
a^3 + b^3 = 243 (given)
ab*(a+b) = 162 (given)
Therefore,
A+b = Cube root of 729 = 9 ..
Q.2 There is a natural number that becomes equal to the square of a natural number when 100 is added to it,and to the square of another natural number when 169 is added to it . Find the number?
(No option)(Plz explain the ans after solving)
DUde,
did this one by pure observation... If some1 knows another method let me know..
If the number becomes a square by adding 169 to it.. that means the no itself is a square.. and the 3 nos constitute a Pythagorous triplet..
Now Pyth Triplets with 13 are: (5,12,13) and (13,84,85)..
The only drawback in this method is that you have to KNOW that 13, 84 and 85 form a triplet..
Anyone knows a better method f this one?
Q.2 There is a natural number that becomes equal to the square of a natural number when 100 is added to it,and to the square of another natural number when 169 is added to it . Find the number?
let the number be = l
let 2 other natural numbers be m and n , such that
m^2= 100+l
n^2= 169+l
n^2-m^2=69=3.(23)
(n-m)(n+m)=3.(23)
clearly, n-m=3 and n+m=23
solving v get n=13 and m=10, from which l =0, which is not a natural number. So, according to me, there is no natural number which satisfies the given conditions.If i hav gone wrong smwhere plz point it out to me.
Q.1 Find two-three digit numbers whose sum is multiple of 504 and the quotient is a multiple of 6.
let the 2 3-digit numbers be n1 and n2
n1+n2= 504k1, where k1 be any integer>=1
n2/n1=6k2, where k2 is any integer>=1
therefore, n2=6k2(n1)
n2+n1=504k1
n1(6k2+1)=504k1
using smallest values, put k2=1 and k1=1
n1.7=504 or n1=72, which is not a 3-digit number, hence v discard this value
take k1=2 and k2=1
n1.7=504.(2)
n1=144, therefore n2=864
Hence, the 2 3-digit numbers are 144 and 864
144+864=1008=504X2
864/144=6=6X1
Q.1 Find two-three digit numbers whose sum is multiple of 504 and the quotient is a multiple of 6.
Q.2 There is a natural number that becomes equal to the square of a natural number when 100 is added to it,and to the square of another natural number when 169 is added to it . Find the number?
Q.3 The sum of the cubes of the digits constituting a two digit number is 243 and the product of the sum of its digits by the product of its digits is 162. Find the two digit number.
(No option)(Plz explain the ans after solving)
hi jogi...
please follow guidelines for posting the questions for sure..it will take less than half time to gef answers to your queries if u follow them..
guide lines are :
Hi all,
i am just overwhelmed after seeing this thread..almost tears in my eyes.
It's indeed great place for people who working on their own, so it's for me!!
Three things All question posting people should take care of are:
1. Specify the Chapter in Heading of Post itself.
2. In Question body specify the question No and LOD I/II/III
3. then write whole question body itself fully word by word as in book.
Additioanlly Whole Solution to perticular question should be given by Clicking on Quote. So it will be easy for people who just landed directly to this scrap.
thanks
Q.1 Find two-three digit numbers whose sum is multiple of 504 and the quotient is a multiple of 6.
Q.2 There is a natural number that becomes equal to the square of a natural number when 100 is added to it,and to the square of another natural number when 169 is added to it . Find the number?
Q.3 The sum of the cubes of the digits constituting a two digit number is 243 and the product of the sum of its digits by the product of its digits is 162. Find the two digit number.
(No option)(Plz explain the ans after solving)
1) 6k+k=504*n
7k=504*n=>k=72n
n can be 1,2 ,3
72*1=72 (rejected)
72*2=144
72*3=216
but 216*6=1878( its not a 3 digit number) thus discarded
The two numbers r 144 and 864
2)n+100=n^2
n+169=m^2
69=(m-n)(m+n)
m-n=3
m+n=23
m=13
n=10
3)a^3+b^3=243
(a+b)*a*b=162
a+b)^3=243+3*162=243+486=729
a+b=9
a*b=3*3*2
thus a=6 n b=3
and the two digit number can be 63 or 36
abhi2400 SaysI am getting the answer as (3) 330/23 (although by a pretty long method), so if the answer is correct then i can post the solution, otherwise there is no point typing my heart out explaining a wrong answer.So, please tell me whether this answer is correct or not
The correct ansr is :330/23. Sorry for the late reply!!
can anybody tell me how much dis book n the one by n.k. sinha cost
and which 1 is better
im kinda avg. in math
can anybody tell me how much dis book n the one by n.k. sinha cost
and which 1 is better
im kinda avg. in math
Dont know about N K Sinha...
Arun Sharma.. is around 300 bucks..
I havent seen NK Sinha... so i wudnt know ... But Arun Sharma definitely seems ot be the more popularly used of the two books...
sinha costs 300,,,got frm nai sarak:neutral:
qn: Vinay fires two bullets from the same place at an interval of 12 mins but shyam who is on a train approaching vinay hears the seacond after an interval of 11 min 30s. speed of sound =330m/s. Find the speed of train.
ans:1. 660/23 2. 220/7 3. 330/23 4. 110/23.
The solution is
The distance travelled by the bullet in 30 sec (12-11.30) = distance travelled by the train in 11 min 30 sec
=> speed s= (330 * 30)/ (11*60 + 30)
= 330/23
The solution is
The distance travelled by the bullet in 30 sec (12-11.30) = distance travelled by the train in 11 min 30 sec
=> speed s= (330 * 30)/ (11*60 + 30)
= 330/23
hey navigator !!
can u navigate me a lil more thru this logic ->:)
"The distance travelled by the bullet in 30 sec (12-11.30) = distance travelled by the train in 11 min 30 sec".
not able to get this one . 😞
Hey ppl,
Need a suggestion ....
im doing Arun Sharma....im solving LOD 1 and 2 only. Plesae suggest if LOD3 also needs to be done. The thing is there is time constraint n i think tat i can complete the book bfore the Mock CATs start and then can analyze them completely...plz suggest if im doing it the RIGHT WAY(if there is ne such thing)
Thanks in Advance...
Cheers.....
Hey ppl,
Need a suggestion ....
im doing Arun Sharma....im solving LOD 1 and 2 only. Plesae suggest if LOD3 also needs to be done. The thing is there is time constraint n i think tat i can complete the book bfore the Mock CATs start and then can analyze them completely...plz suggest if im doing it the RIGHT WAY(if there is ne such thing)
Thanks in Advance...
Cheers.....
Whether it is the right way or not is what u feel is right and ur "comfort level".... But make sure u do important topics nicely form Arun Sharma.. or any standard text book if ur using 1 apart form the materials... topics like Number Systems, Geometry...
question:
the ratio of the factorial of a number x to the square of the factorial of another number, which when increased by 50% gives the required number, is 1.25. Find the number x.
options are (a) 6 (b) 5 (c) 9 (d) 2
the answer is (a) 6.
this can be very easily solved using the options. But what i want is a method to solve it without using the options. Please try it out.
hi every1
Q Find the units digit of the expression
78^5562 X 56^256 X 97^1250
in this ques wat m not getting is
that 5562 = 8n+2 so that means we can write it as
78^2 X 78^8n that now is it because of the first term(78^2) that we wil simply say that units place wil be 4 coz 8^2=64.
is there no need to see 78^8n??
but if we go by this method than
1250= 7n+4
97^4 X 97^7n that means units digit should be equal to 7^4 that is 1 but in this case its 9??
please xplain where m screwing the problem??
hi every1
Q Find the units digit of the expression
78^5562 X 56^256 X 97^1250
in this ques wat m not getting is
that 5562 = 8n+2 so that means we can write it as
78^2 X 78^8n that now is it because of the first term(78^2) that we wil simply say that units place wil be 4 coz 8^2=64.
is there no need to see 78^8n??
but if we go by this method than
1250= 7n+4
97^4 X 97^7n that means units digit should be equal to 7^4 that is 1 but in this case its 9??
please xplain where m screwing the problem??
try it this way....
the units digit of a number raise to power something depends on the units digit of number
so the ques reduces to units digit of
8^5562 * 6^256 *7^1250
now 8^1 gives units digit 8
8^2......................4
8^3.......................2
8^4.......................6
8^5......................8
this means cyclicty so of 8 is 4...so dividing 5562 by 4 we get remainder 2
i.e. 8^5562 is eqult. to 8^2 so it gives unit digit 4
similarly 6 raise to power has cyclicity of 1 so 6^256 give unit digit 6
...........7..........................................4 so 7^1250 ................. 9
therefore ques rduces to 4*6*9
i.e 6 ans......