A can do a work in 18days, B in 9 days and C in 6 days. A and B start working together and after 2 days C joins them. What is the total number of days taken to finish the work?

Answer: B (A+B)'s 2 days work = 2(1/18 + 1/9) = 1/3 Remaining work = 1- 1/3 = 2/3. (A+B+C)'s one days work = (1/18 + 1/9 +1/6) = 1/3. 1/3 work is completed working all of them together in one day. Hence, 2/3 work will be completed in 2 days. Thus, Total number of days taken to finish the work is 4 days.

Q. No. 2:

A worker is paid Rs 56 for 35 hour week. Upto 40 hour, he is paid at the normal rate and on overtime, 1.5 times the normal. How many hours did he work to get Rs88?

Answer: C Let the worker worked for (40+x) hours, then (56/35 * 40) + (x*1.5*56)/35 = 88 2.4 x = 88 => x=10. The worker worked for (40+10) = 50 hour.

Q. No. 3:

Two pipes can fill the cistern in 10hr and 12 hr respectively, while the third empty it in 20hr. If all pipes are opened simultaneously, then the cistern will be filled in

Answer: A Work done by all the tanks working together in 1 hour => 1/10 + 1/12 - 1/20 = 2/15 Hence, tank will be filled in 15/2 = 7.5 hour.

Q. No. 4:

A and B weave a carpet in 10 days and 15 days respectively. They begin to work together but B leaves after 2 days. In what time will A complete the remaining work?

Answer: D (A+B)'s one day work = 1/10 + 1/15 = 1/6 (A+B)'s two days work = 1/3. Hence, remaining 2/3 work will be done by A alone in => 10 * 2/3 = 20/3 hour.

Q. No. 5:

I can do a piece of work in 8 days, which can be done by you in 10 days. How long will it take to do it if we work together?

Answer: A Work done by both = 1/8 + 1/10 = 9/40 in 1 day. One work will be completed by them in 40/9 days.

Q. No. 6:

A contractor undertook to do a piece of work in 9 days.He employed certain number of labourers but 6 of them being absent from the very first day, the rest could finish the work in 15 days. Find the number of men originally employed?