21. A can do a work in 12 days and B can do it in 16 days. If they work together for 4 days and then A leaves, how long will B take to finish the remaining work?
a) 6 days
b) 5 days
c) 4 days
d) 3 days
The correct answer is: A
22. A can complete a task in 30 days, B in 40 days, and C in 60 days. If they work together, how long will it take to complete the task?
a) 12.33 days
b) 13.33 days
c) 14.33 days
d) 11.33 days
The correct answer is: B
23. If A and B together can complete a work in 8 days and A alone can complete it in 12 days, how long will B take to complete the work alone?
a) 18 days
b) 24 days
c) 16 days
d) 20 days
The correct answer is: B
24. A can complete a work in 14 days and B can complete the same work in 28 days. If they work together for 7 days and then B leaves, how long will A take to finish the remaining work?
a) 4.5 days
b) 5.5 days
c) 3.5 days
d) 6.5 days
The correct answer is: C
25. If 7 men can build a wall in 14 days, how long will it take for 14 men to build the same wall?
a) 10 days
b) 8 days
c) 6 days
d) 7 days
The correct answer is: A
