out of 12 people 3 people can sit on only one side and 2 on other.so we have to choose out of seven people.let us take for the first side of boat.we have to choose 1peron out of seven.when this person is chosen we can choose 2 people out of six for the another row.
so the answer is=7C1*6C2*!4*!4=60480 cheers!!!!
why are we not considering the case when none of the 3 ppl who can row from a particular side are selected.similarly for other 2 ppl?? why 7c1.? for this side we have 10 ppl eligible rt?
Numbers divisible by 2 are 102,104,.........,398 Total Number of numbers divisible by 2 398 = 102 + (n-1)2 n = 149 Numbers divisible by 3 are 105,111,.........,399 (excluding the even numbers) Total Number of numbers divisible by 3 and not by 2 (as 2 has already been included) 399 = 105 + (n-1)3 n = 50 Numbers divisible by 5(and not by 2 and 3) are 115,125,145,155,175,185,205,215,235,245.........,395 n= 4 x 6 = 20 Numbers divisible by 7(and not by 2,3,5) are 119,133,161..............,385 n = 11
Ans = 149 + 50 + 24 + 12 = 230
Guys, let me know if the answer is incorrect. however, this is a very crude way of solving it. Plz post any other method for solving such questions.
@abhijit111 plz see the one in bold red... The equation that you made over here is wrong as there is a difference of 6. So, Eqn is 399 = 105 + (n-1) 6 (" You are using the A.P formula rt") & how you get this 4 * 6?. Did you actually sit & count Numbers divisible by 7(and not by 2,3,5)... Is there any other way to do it?
@abhijit111 plz see the one in bold red... The equation that you made over here is wrong as there is a difference of 6. So, Eqn is 399 = 105 + (n-1) 6 (" You are using the A.P formula rt") & how you get this 4 * 6?. Did you actually sit & count Numbers divisible by 7(and not by 2,3,5)... Is there any other way to do it?
Hi, I didn't get your doubt properly. As far as I remember, the equation is for numbers divisible by 2 398 = 102 + (n-1) 2 and later since even numbers (divisible by 2) have already been counted, numbers with a diff of 6 have been taken 105,111,117,.... And the other equation should have 6 instead of '3' (You are correct, just a typing mistake) .. But 50 is the correct answer for that.. I do agree. thanks for pointing it out.
Ques . In a mixture of petrol and kerosene percentage of kerosene was 18%, eight litre of mixture was taken out and was replaced with petrol the percentage of kerosene after this was 15%. What was the initial volume of the mixture?
The answer for this is 48L. But I want to know the approach for this kind of problems
Ques . In a mixture of petrol and kerosene percentage of kerosene was 18%, eight litre of mixture was taken out and was replaced with petrol the percentage of kerosene after this was 15%. What was the initial volume of the mixture?
The answer for this is 48L. But I want to know the approach for this kind of problems
======================================================= There can be many approaches to solve questions of this type. I am giving one approach here... let there be x litres of mixture . Now, 0.18x is kerosene and 0.82x is petrol. After withdrawing 8 litres, the qty of liquids left kerosene =(x-8 ) * 0.18 petrol =(x-8 ) * 0.82 %ge of kerosene in the final mixture
(x- 8 ) * 0.18 -------------- * 100 = 15 x hence (x-8 ) 18 = 15x or x =48 litres..
Q1.> In how many ways 10 identical presents can be distributed among 6 children ,so that each child gets atleast one present.
(a) C(15,5) (b) C(16,6) (c) C(9,5) (d) 6^10
Q2.> In how many ways can Ram choose one vowel and one consonant from the letters of the word ALLAHABAD ?
(a)4 (b)6 (c)9 (d)5
Q3.>There are ten subjects in the school day at ST. vincent 's high school ,but the sixth standard students have only 5 periods in a day. In how many ways can we form a time table for the day for the sixth standard students ?
(a)5^10 (b)10^5 (c)252 (d)30240
Q4.> There are 5 blue socks,4 red socks and 3 green socks in Debu's wardrobe .He has to select 4 socks from this set.In how many ways can he do so ?
(a)245 (b)120 (c)495 (d)60
Q5.> How many 7-digit numbers are there having the digit 3 three times and the digit 5 four times ?
(a) 7!/(3!)(5!) (b)3^3 * 5^5 (c)7^7 (d)35
More questions to follow............ :)......:2gunfire:.............waiting for answers:popcorn:
hello friends, I have a lot of doubts in the 'Inequalities' chapter. Even after putting a lot of effort I am hardly getting the answers correctly. I have tried to look for similar questions(the one's given in Arun Sharma) in other books, but couldn't find them anywhere. if any of you have your fundas clear in this chapter ,kindly help me out. I am posting one question for example. Any one who solves it, kindly post the steps also and the reasons for selecting that particular answer. LOD - I Q- 68 Solve the following inequalities :grab: x-17 >= 60/x a) x= 20 d) -3= 20
hello friends, I have a lot of doubts in the 'Inequalities' chapter. Even after putting a lot of effort I am hardly getting the answers correctly. I have tried to look for similar questions(the one's given in Arun Sharma) in other books, but couldn't find them anywhere. if any of you have your fundas clear in this chapter ,kindly help me out. I am posting one question for example. Any one who solves it, kindly post the steps also and the reasons for selecting that particular answer. LOD - I Q- 68 Solve the following inequalities :grab: x-17 >= 60/x a) x= 20 d) -3= 20
Thanks in Advance...
IS answer C???Let me know i will explain u my method......
ya the answer is c. Please explain me the procedure...
Ok here it goes x-17-x/60 > =0 (x^2-17x-60)/x > = 0 Now multiply Nr Dr by x So Dr becomes x^2 which is always +ve So for Nr to b + either X>0 or x^2-17x-60>0 or X Solve eqns and find common region....Revert if still any issues
hey, i've a doubt in a problem. its easy but i dunno why my answers r not matching. Find the least number which when divided by 16,18, and 20 leaves a remainder 4 in each case, but is completely divisible by 7. (a) 364 (b) 2254 (c) 2884 (d) 3234
MY METHOD : LCM of 16,18,20 = 720 720+4 = 724 but 724 is not divisible by 7, so we need 2 find the LCM of 724 & 7, ie 724 * 7 = 5068 answer : 5068
hey, i've a doubt in a problem. its easy but i dunno why my answers r not matching. Find the least number which when divided by 16,18, and 20 leaves a remainder 4 in each case, but is completely divisible by 7. (a) 364 (b) 2254 (c) 2884 (d) 3234
MY METHOD : LCM of 16,18,20 = 720 720+4 = 724 but 724 is not divisible by 7, so we need 2 find the LCM of 724 & 7, ie 724 * 7 = 5068 answer : 5068
where am i wrong? or am i correct?
Upto Ur finding the LCM its alright. Now 724%7 = 3. Now U've to satisfy 3m%7 =0, & then multiply 724 with m to get the answer. Here, in this case, as 3 & 7 are co-prime U're getting the correct answer.
Upto Ur finding the LCM its alright. Now 724%7 = 3. Now U've to satisfy 3m%7 =0, & then multiply 724 with m to get the answer. Here, in this case, as 3 & 7 are co-prime U're getting the correct answer.
Sorry for my previous post: Correct answer can be achhieved as follows.
LCM = 720.
Reqired no. Should satisfy, N = 720m + 4 so that (720m + 4)%7 = 0.
U can easily find out m = 4. thus N = 720*4 +4 =2884.
Ignore my previous post.
Cheers Arnab
@ Arnab ... what u did is correct but we will have to check the options for answer by putting different values of m OR u can do it like 720m + 4 = options... & the only option which satisfy this is 2884.
@ Arnab ... what u did is correct but we will have to check the options for answer by putting different values of m OR u can do it like 720m + 4 = options... & the only option which satisfy this is 2884.
In this case, U can ofcourse go for answer options. But there may be some cases where U may get confused.
Any way, U can use more shortcut method as follows. LCM = 720. No is 720m + 4. Now all u have to find m to get the answer. Check for 720%7 which results in 6. Now U can easily find out m from instead of . m comes to be 4 & so the answer is 720*4 + 4 = 2884.
I have two Q.,whoever solves plz explain the solution
Q.1 If a,b,c,d are in continued proportion then ((a-d)/(b-c)) >= x. What is the value of x. a) 2 b)3 c)1 d)0
Q).2 The difference between simple and compound interest on a some of money at 5% per annum is Rs. 25. What is the sum. a) Rs. 5000 b)Rs 10,000 c) Rs 4000 d) Data Insufficient
If anybody would like to discuss on this problem, i m readily available.
What i think on the second Q. is that it is wrong. As we know the diff is (P*r^2)/(100^2) for t=2 yrs( Which is not given). If we use it we will get option b) as ans.
I have two Q.,whoever solves plz explain the solution
Q.1 If a,b,c,d are in continued proportion then ((a-d)/(b-c)) >= x. What is the value of x. a) 2 b)3 c)1 d)0
Q).2 The difference between simple and compound interest on a some of money at 5% per annum is Rs. 25. What is the sum. a) Rs. 5000 b)Rs 10,000 c) Rs 4000 d) Data Insufficient
If anybody would like to discuss on this problem, i m readily available.
What i think on the second Q. is that it is wrong. As we know the diff is (P*r^2)/(100^2) for t=2 yrs( Which is not given). If we use it we will get option b) as ans.
What u guys think?
for the 1st question--> i think continued proportion means somthing like 1:2:3:4.
then a-d will always result in 3 and b-c in 1 .Hence x will always be 3 . option(b)
for the 2nd question --> wats the answer ?? if the time is not given we may take it as one yr ,coz consedering it 1yr we do not require time at all.
There can be many approaches to solve questions of this type. I am giving one approach here...
I have a lot of doubts in the 'Inequalities' chapter. Even after putting a lot of effort I am hardly getting the answers correctly. I have tried to look for similar questions(the one's given in Arun Sharma) in other books, but couldn't find them anywhere. if any of you have your fundas clear in this chapter ,kindly help me out. I am posting one question for example. Any one who solves it, kindly post the steps also and the reasons for selecting that particular answer