12
Q:

# The ratio of efficiency of A is to C is 5:3. The ratio of number of days taken by B is to C is 2:3. A takes 6 days less than C, when A and C completes the work individually. B and C started the work and left after 2 days. The number of days taken by A to finish the remaining work is:

 A) 4.5 B) 5 C) 6 D) 9 1/3

Explanation:

A     :    B    :    C

Efficiency     $\inline&space;\fn_jvn&space;\rightarrow$         10    :    9    :     6

No of days   $\inline&space;\fn_jvn&space;\rightarrow$         9x    :  10x   :    15x

$\inline&space;\fn_jvn&space;\Rightarrow$       15x-9x = 6

$\inline&space;\fn_jvn&space;\therefore$             x = 1

Number of days taken b A = 9

Number of days taken by B= 10

Number of days taken by C = 15

work done by B and C in initial 2 days = $\inline&space;\fn_jvn&space;\frac{2\times&space;1}{6}$ = $\inline&space;\fn_jvn&space;\frac{1}{3}$

rest work =$\inline&space;\fn_jvn&space;\frac{2}{3}$

Number of days required by A to finish $\inline&space;\fn_jvn&space;\frac{2}{3}$ work = $\inline&space;\fn_jvn&space;\frac{2/3}{1/9}$ = 6 days

Q:

Sixty men can stitch 150 shirts in 30 days working 8 hours a day. In how many days can 35 men stitch 200 shirts working 6 hours a day ?

 A) 87.5 B) 89 C) 91.5 D) 93.5

Explanation:

We have M1 D1 H1 / W1 = M2 D2 H2 / W2 (Variation rule)
(60 x 30 x 8)/ 150 = (35 x D2 x 6) / 200
D2 = (60 x 30 x 8 x 200) / (150 x 35 x 6) => D2 = 91.42 days =~ 91.5 days.

1 7
Q:

A can complete a piece of work in 12 days and B is 60% more efficient than A. In how many days B will complete the same work  ?

 A) 8.7 hrs B) 5.2 hrs C) 5 hrs D) 7.5 hrs

Explanation:

Ratio of times taken by A and B = 160 : 100
A can do the work in 12 days
Let B can do the work in "D" days
=> 160:100 = 12 : D
=> D = 12 x 100/160 = 7.5 hrs

2 40
Q:

A can finish a work in 18 days and B can do the same work in half the time taken by A. then, working together, what part of the same work they can finish in a day ?

 A) Total work B) One-fourth work C) Half work D) Two-third work

Explanation:

A can do the work = 18 days
B can do the work = 18/2 = 9 days
(A + B)'s 1 day work = 1/18 + 1/9 = 1/6
=> In 3 days = 3x1/6 = 1/2 work is completed.

1 31
Q:

10 boys can complete a work in 7 days and 10 girls take 14 days to complete the work. How many days will 5 boys and 10 girls take to complete the work ?

 A) 13 days B) 10 days C) 7 days D) 16 days

Explanation:

1 boy's 1 day work = 1/70
1 girl's 1 day work = 1/140
(5 boys + 10 girls)'s 1 day work
= (5/70 + 10/140) = (1/14 + 1/14) = 1/7

5 boys and 10 girls will complete the work in 7 days.

2 44
Q:

A is 30% more efficient than B. How much time will they, working together, take to complete a job which A alone could have done in 23 days  ?

 A) 9 days B) 11 days C) 13 days D) 15 days

Explanation:

Ratio of times taken by A and B = 100 : 130 = 10 : 13.
Suppose B takes x days to do the work.

Then, 10 : 13 :: 23 : x     =>     x = ( 23 x 13/10 )     =>     x = 299 /10.

A's 1 day's work = 1/23 ;
B's 1 day's work = 10/299 .

(A + B)'s 1 day's work = ( 1/23 + 10/299 ) = 23/299 = 113 .

Therefore, A and B together can complete the work in 13 days.