9
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 = 36/6 = 6
Number of pages typed by Smith in 1 hour = 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) = $8\frac{4}{7}$ = 8 hrs 34 min.

Q:

If 2 men and 3 women can do a piece of work in 8 days and 3 men and 2 women in 7 days. In how many days can the work be done by 5 men and 4 women working together?

 A) 3 days B) 6 days C) 4 days D) 2 days

Explanation:

From the given data,

=> (2 M + 3W) 8 = (3M + 2W)7

=> 16M + 24W = 21M + 14 W

=> 10W = 5M

=> 2W = M

=> 14W × ? = 7W × 8

? = 4 days

12 1958
Q:

28 Men and 52 women working together completes a work in 22.5 days. 35 men and 65 women working together on same work will complete it in how many days?

 A) 16 B) 18 C) 19 D) 21

Explanation:

Clearly total persons are increased in  28/35 :: 52/65 = 4:5.

As time is inversely proportional to men, so total time will decrease in the ratio 5:4.

Hence, 22.5 x 4/5 = 18 days.

8 826
Q:

X can complete the work in 10 days, Y can do the same in 15 days. If they are hired for 5 days to do the work together, what is the work that left unfinished?

 A) 1/3 B) 2/3 C) 1/6 D) 5/6

Explanation:

Given X can do in 10 days

=> 1 day work of X = 1/10

Y can do in 15 days

=> 1 day work of Y = 1/15

1day work of (X + Y) = 1/10 + 1/15 = 1/6

Given they are hired for 5 days

=> 5 days work of (X + Y) = 5 x 1/6 = 5/6

Therefore, Unfinished work = 1 - 5/6 = 1/6

10 974
Q:

If 10 men take 15 days to complete a work. In how many days will 37 men complete the work?

 A) 3 days B) 4 days C) 5 days D) 6 days

Explanation:

Given 10 men take 15 days to complete a work

=> Total mandays = 15 x 10 = 150

Let the work be 150 mandays.

=> Now 37 men can do 150 mandays in 150/37 =~ 4 days

14 795
Q:

Three taps P, Q and R can fill a tank in 12 hrs, 15 hrs and 20 hrs respectively. If P is open all the time and Q and R are open for one hour each alternately, starting with Q, then the tank will be full in how many hours ?

 A) 9 hrs B) 7 hrs C) 13 hrs D) 11 hrs

Explanation:

Given,

P can fill in 12 hrs

Q can fill in 15 hrs

R can fill in 20 hrs

=> Volume of tank = LCM of 12, 15, 20 = 60 lit

=> P alone can fill the tank in 60/12 = 5 hrs

=> Q alone can fill the tank in 60/15 = 4 hrs

=> R alone can fill the tank in 60/20 = 3 hrs

Tank can be filled in the way that

(P+Q) + (P+R) + (P+Q) + (P+R) + ....

=> Tank filled in 2 hrs = (5+4) + (5+3) = 9 + 8 = 17 lit

=> In 6 hrs = 17 x 6/2 = 51 lit

=> In 7th hr = 51 + (5+4) = 51 + 9 = 60 lit

=> So, total tank will be filled in 7 hrs.

9 1506
Q:

P and Q can complete a job in 24 days working together. P alone can complete it in 32 days. Both of them worked together for 8 days and then P left. The number of days Q will take to complete the remaining work is ?

 A) 56 days B) 54 days C) 60 days D) 64 days

Explanation:

(P+Q)'s 1 day work = 1/24

P's 1 day work = 1/32

=> Q's 1 day work = 1/24 - 1/32 = 1/96

Work done by (P+Q) in 8 days = 8/24 = 1/3

Remainining work = 1 - 1/3 = 2/3

Time taken by Q to complete the remaining work = 2/3 x 96 = 64 days.

8 1824
Q:

A can complete 9/10 part of a work in 31 days. After that, with the help of B he can complete the remaining work in 4 days. In how many days will  A and B together can complete that work ?

 A) 36 B) 40 C) 42 D) 38

Explanation:

Remaining work = 1 - 9/10 = 1/10

=> A & B together completes 1/10 of work in 4 days

=> 1 work can completed in ------ ? days

Let it be x days

=>  $\frac{4}{\frac{1}{10}}=\frac{x}{1}$

=> x = 40 days.

Hence, A & B together can complete the work in 40 days.

8 650
Q:

P alone can do a piece of work in 24 days. The time taken by P to complete one-third of work is equal to time taken by Q to complete half of the work. How many days are required to complete by P and Q working together ?

 A) 9 3/5 days B) 7 days C) 6 3/7 days D) 8 days

Explanation:

Let the total work be 'W'

As per the given information,

P can complete the work 'W' in 24 days.

=> one day work of P = W/24

And also given that,

The time taken by P to complete one-third of work is equal to time taken by Q to complete half of the work

=> PW/3 = QW/2

=> P's

1 day =    W/24

?    =      W/3

=>  ?  = 24W/3W  = 8

=> QW/2 = 8 days

=> Q alone can complete the work W in 16 days

=> P + Q can complete the work in

1/24 + 1/16 = 5/48

=> 48/5 days = 9 3/5 days.