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

1. If 8 men cane reap 80 hectares in 24 days , then how many hectares can 36 men reap in 30 days ?

1. If 12 carpenters , working . 6 hours a day , can make 460 chair in 24 days , how many chairs will 18 carpenters make in 36 days each working 8 hours a day .

1. If 18 binders bind 900 books in 10 days  , how many binders will be required to bind 660 books in 12 days ?

1. A rope  makes 70 rounds of the circumference of a cylinder whose radius of the base  is 14 cm. How many times can it go round a cylinder with radius 20 cm ? 

1. Some person can do a piece of work in 12 days . Two times the numbers of persons will do half of that work  in how many days ?

1. A garrison of 500 men had provisions for  27 days . After 3 days a reinforcement of 300 men arrived . For how many more days will the remaining food last now ?

1. 15 men take 21 days of 8 hours each to do a piece of work. How many days of 6 hours each would 21 women take , if 3 women do as much work as 2 men ?

1. If 3 men or 6 boys can do a piece of work in 10 days , working  7 hours a day ; how many days will it take to complete a piece of work twice as large with 6 men and 2 boys working together for 8 hours a day ?

2 men and  7  boys can do a piece of work in 14 days ; 3 men and 8 boys can do the same in 11 days . Then , 8 men and 6 boys can do three times the amount of this work in .