8
Q:

# Adam and Smith are working on a project. Adam takes 6 hrs to type 36 pages on a computer, while Smith takes 5 hrs to type 40 pages. How much time will they take, working together on two different computers to type a project of 120 pages?

 A) 8 hrs 45 min B) 8 hrs 42 min C) 8 hrs D) 8 hrs 34 min

Answer:   D) 8 hrs 34 min

Explanation:

Number of pages typed by Adam in 1 hour = $\inline \fn_jvn \small \frac{36}{6}$ = 6
Number of pages typed by Smith in 1 hour = $\inline \fn_jvn \small \frac{40}{5}$ = 8
Number of pages typed by both in 1 hour = (6 + 8) = 14
Time taken by both to type 110 pages = (120 * 1/14) = 8 $\inline \fn_jvn \small \frac{4}{7}$ = 8 hrs 34 min.

Q:

A is 3 times faster than B. If A can finish a work 32 days less than that of B, find the number of days need to finish the work if both are working together?

 A) 12 days B) 24 days C) 32 days D) 16 days

Explanation:

It is given that efficiency ratio =3:1, so time ratio will be 1:3 (since work is same)

also given that time diff = 32 days. ratio difference = 3-1 =2

2 ratio = 32 days

1 ratio = 16 days. So A will alone finish it in 16 days and B will finish it in 16*3 = 48 days.

Total work LCM of 16 and 48 = 48. Total time = Total work/Total efficiency

ie; 48/4= 12 days....

2 6
Q:

K, L and M can do a piece of work in 20, 30 and 60 days respectively. In how many days can K do the total work if he is assisted by L and M on every third day ?

 A) 15 days B) 13 days C) 12 days D) 10 days

Explanation:

In one day work done by K = 1/20
Work done by K in 2 days = 1/10
Work done by K,L,M on 3rd day =1/20 + 1/30 + 1/60 = 1/10
Therefore, workdone in 3 days is = 1/10 + 1/10 = 1/5
1/5th of the work will be completed at the end of 3 days.
The remaining work = 1 - 1/5 = 4/5
1/5 of work is completed in 3 days
Total work wiil be done in 3 x 5 = 15 days.

3 30
Q:

A shopkeeper has a job to print certain number of documents and there are three machines P, Q and R for this job. P can complete the job in 3 days, Q can complete the job in 4 days and R can complete the job in 6 days. How many days the shopkeeper will it take to complete the job if all the machines are used simultaneously ?

 A) 4/3 days B) 2 days C) 3/2 days D) 4 days

Explanation:

Let the total number of documents to be printed be 12.
The number of documents printed by P in 1 day = 4.
The number of documents printed by Q in 1 day = 3.
The number of documents printed by R in 1 day = 2.
Thus, the total number of documents that can be printed by all the machines working simultaneously in a single day = 9.
Therefore, the number of days taken to complete the whole work = 12/9 = 4/3 days.

4 14
Q:

Twelve children take sixteen days to complete a work which can be completed by 8 adults in 12 days. After working for 3 days, sixteen adults left and six adults and four children joined them. How many days will they take to complete the remaining work ?

 A) 3 days B) 2 days C) 6 days D) 12 days

Explanation:

From the given data,
12 children 16 days work,
One child’s one day work = 1/192.
One adult’s one day’s work = 1/96.
Work done in 3 days = ((1/96) x 16 x 3) = 1/2
Remaining work = 1 – 1/2 = 1/2
(6 adults+ 4 children)’s 1 day’s work = 6/96 + 4/192 = 1/12
1/12 work is done by them in 1 day.
1/2 work is done by them in 12 x (1/2) = 6 days.

4 15
Q:

After working for 8 days, Arun finds that only $\inline \fn_jvn \small \frac{1}{3}$ rd of the work has been done. He employs Akhil who is 60% as efficient as Arun. How many days more would Akhil take to complete the work?

 A) 24.5 days B) 26.6 days C) 25 days D) 20 days

Explanation:

Arun has completed $\inline \fn_jvn \small \frac{1}{3}$ rd of the work in 8 days
Then he can complete the total work in
$\inline \fn_jvn \small \frac{1}{3}$ ---- 8
1 ---- ?
= 24 days
But given Akhil is only 60% as efficient as Arun
Akhil = $\inline \fn_jvn \small \frac{1}{24}\times \frac{60}{100}=\frac{1}{40}$
Akhil can complete the total work in 40 days
Now, remaining 2/3rd of work can be completed in
1 ------   40
$\inline \fn_jvn \small \frac{2}{3}$  ------   ?   $\fn_jvn&space;\small&space;\Rightarrow$ 26.66 days.