Time & Work, Chain Rule

A computer takes 50 nanoseconds to do an addition. How many additions can it do in 1 seconds?

A takes twice as much time as B or thrice as much time as C to finish a piece of work. Working together, they can finish the work in 2 days. B can do the work alone in :

P works twice as fast as Q. If Q can complete a work in 12 days independently, the number of days in which P and Q can together finish the work is -

A man's regular pay is Taka 30 per hour up to 40 hours. Overtime is twice the payment for regular time. If he was paid taka 1680, how many hours overtime did he work? 

A is 30% more efficient than B. How much time will they, working together, take to complete a job which A alone could have done is 23 days?

A can do a work in 20 days, and B in 30 days. They work together for 6 days. How much of the work is left?

If a light flashes every 6 seconds, how many times will it flash in 3/4 of an hour?

A man walks 10m east but runs 5m west every day. How many days will it take him to cross a building 380m east?

A pump remover's water at a rate of 6 gallons per minute. How many hours will it take to remove 1800 gallons?

A monkey climbs a 60m high pole. In first minute he climbs 6m and slips down 3m in the next minute. How much time is required by it to reach the top? 

Courier charges for packages to a certain destination are Tk. 65 for the first 250 grams and Tk 10 for each additional 100 grams or part thereof. What could be the weight in grams of a package for which the charge is Tk. 155?

3 pumps, working 8 hours a day, can empty a tank in 2 days. How many hours a day must 4 pumps work to empty the tank in 1 day?

A, B and C working individually can complete a task in 30 days, 15 days and 10 days respectively. If A starts working alone and B and C helps A on every 2^nd and 3^rd day respectively, how long will it take the task to be completed?

Hassan completed 1/3 portion of a job in 8 days and left. Then Jashim was recruited and he worked for 5 days and left the job. Hassan again joined and completed the rest of the work in 12 days. How many days would Jashim require to complete the job alone?

If 40 men can make 30 boxes in 20 days. How many more men are needed to make 60 boxes in 25 days?

A and B can do a piece of work in 9 days, B and C in 12 days, A and C in 18 days. If all of them work together, then how much time will they take to finish the same work?

Painter A can paint a house in 16 days, and painter B can do the same work in 20 days. With the help of painter C, they paint the house in 8 days only. Then, Painter C alone can do this task in -

If 12 men work on a particular task. It takes them 24 days to complete it. On the other hand 12 women can complete the same task in 12 days. How many days would it take if the 12 man and 12 women complete with each other to finish the same task?

What is the maximum number of half-point bottles of cream that can be filled with a 4- gallon can of cream? (2 pt. = 1 qt. and 4 qt. = 1 gal)

A and B can do a work in 12 days. B and C can do it in 15 days. A and C can do it in 20 days. If all of them work together, in how many days can they finish the work?