M4maths Previous Puzzles

02 Feb 2011 Find the number of days

4 boys complete 2/3 of a work in 10 days. How many days are required for completing 3/4 of the work by 5 boys?

OPtion

1. 8
2. 9
3. 7
4. 6
5. 10
6. 11
7. 12
8. 13
9. 5
10. 14

Solution

4 boys--------------2/3 work------------------10 days
4 boys--------------1 work--------------------10/ (2/3) days
1 boy---------------1 work-------------------- 15*4 days
5 boys--------------1 work--------------------60/5 days
5 boys-------------3/4 work----------------12*3/4 =9 days

Correct Option: 2 Best Solution (13)

Dimple   14 years AGO

Total man / boy days reqd to complete one work = 10 *4*3/2= 60.
hence days required for completing 3/4 of the work by 5 boys = (60/5)*3/4= 9

Like? Yes (5) | No   

HARMEET KAUR   14 years AGO

Days required = 4x10x(3/2)x(3/4)/5 =9

Like? Yes (4) | No   

Jason   14 years AGO

4 boys complete 2/3 of a work in 10 days.
days required for completing 3/4 of the work by 5 boys = [10*(2/3)*4] *(3/4)/5= 9 days

Like? Yes (3) | No   

Karan   14 years AGO

4 boys complete 2/3 of a work in 10 days.
1 boy completes 1 of a work in 10*(3/2)*4 days =.60 days
5 boys complete 3/4 of a work in days= 60*(3/4)/5=9 days

Like? Yes (3) | No   

A.P.Singh   14 years AGO

4 boys complete 2/3 of a work in 10 days.
4 boys complete total work in 15 days.
1 boy completes work in 60 days.
5 boys complete work in 60/5=12 days.
5 boys complete 3/4 work in 12*3/4=9 days.

Like? Yes (3) | No (2)  

Seema   14 years AGO

(4*10)/(2/3)=(5*x)/(3/4)

x=9
(where x is number of days required)by 5b to do 3/4 work

Like? Yes (2) | No (1)  

Suresh Varma P   14 years AGO

Let us take days required to complete 3/4 of work by 5 boys is D then: (assuming same work)

4 * 10/(2/3) = 5 * D/(3/4)
D = 9 days
Option: 2 (ans)

Like? Yes (2) | No (2)  

goutam Choudhury   14 years AGO

4 boys can do the full work in 10*3/2=15 days. 5 boys do the full work in 15*4/5=12 days, and 3/4th of the work will be done by 5 boys in 12*3/4=9 days.

Like? Yes (1) | No (1)  

Sneha Latha M   14 years AGO

m1d1/w1=m2d2/w2
By using the above formula we can get the number of days that 5 boys can complete 3/4 of the work.
so the answer is 9 and the option is 2

Like? Yes (2) | No (2)  

SUJIT PATTANAYAK   14 years AGO

4 boy completes 2/3 w in 10 days
1 boy 2/3 w in 40 days
1 boy 1 w in 40x 3/2 = 60 days
1 boy 3/4 w in 60 x 3/4 = 45 days
5 boys 3/4 w in 45/5 = 9 ays

so, the ans is 2. 9 days

Like? Yes (1) | No (2)  

shobha goutam   14 years AGO

W=m*t
M*t/w=m*t/w
4*10/(2/3)=5*t/(3/4)
T=9

Like? Yes (1) | No (2)  

SUDESHNA SEN   14 years AGO

{10*4*(3/4)}/{(2/3)*5}= 9..... Option 2)

Like? Yes (1) | No (2)  

RAVI   14 years AGO

4*10/(2/3)=5*X/(3/4)
x=9

Like? Yes (1) | No (2)