Q.1 If 3 men & 5 women can do a piece of work in 8 days & 2 men & 7 children do the same piece of work in 12 days. How many women can do as much work in a day as 21 children ?
A) 15
B) 10
C) 7
D) 12
Ans. B
If in 8 days the work can be done by 3 men+5women
Therefore, in 1 day the work can be done by
8 (3 men + 5 women)
24 men + 40 women
Again if in 12 days the work can be done by 2 men + 7 children
Therefore, if in 1 day the work can be done
12 (2 men + 7 children)
24 men + 84 children
Work of 24 men & 40 women = work of 24 men & 84 children
Work of 84 children = work of 40 women
Work of 1 children = work of 40/84 women
Therefore, work of 21 children = work of 40*21 / 84 women
= work of 10 women
Q.2 When Manish alone can do a piece of work , he takes 16 days more than the time taken by Manish & Anuj together to complete the work while Anuj takes 9 days more than the time taken by Manish & Anuj together to complete the work. What time Manish & Anuj together will take to complete the work ?
A) 10 days
B) 11 days
C) 12 days
D) 13 days
Ans. C
Q.3 Number of men can do a piece of work in 24 days. If there were 5 men less the work could be finished in 8 days more. How many men were initially present at the work ?
A) 20
B) 21
C) 22
D) 23
Ans. A
Shortcut :
a(D + d) / d
i.e. 5 (24 + 10) / 8 = 5*32 / 8 = 20
Q.4 Sunil completes a work in 4 days where Dinesh completes the work in 6 days. Ramesh works 1 ½ times as fast as sunil. Three together can complete the work in:
A) 1 5/12
B) 1 5/7
C) 1 3/8
D) 1 5/19
Ans. D
Number of days taken by Ramesh = 4*2/3 = 8/3
Thus, x=4, y=6, z=8/3
Therefore, xyz / xy + yz +zx
On Solving, we will get
1 5/19
Q.5 Three persons undertake to complete a work inRs.1200. The first person can complete a work in 8 days, second person in 12 days & third person in 16 days. They complete the work with the help of fourth person in 3 days. What does the fourth person get ?
A) Rs. 225
B) Rs. 250
C) Rs. 200
D) Rs. 180
Ans. A
Let fourth person works in x days
Thus, 1/8 + 1/12 + 1/16 + 1/x = 1/3
Or 1/x = 1/3- 1/8 -1/12 – 1/16
Or 16-6-4-3 / 48 = 3/48 = 1/16
Or x=16
Now, ratio of work done by first, second, third & fourth person
= 1/8 : 1/12 : 1/16 : 1/16 = 6:4:3:3
Thus , Amount by fourth person is: 3/16 * 1200 = Rs.225
