Level 3
A farmer had twice as many chickens as ducks. After he had sold 200 chickens, he had thrice as many ducks as chickens. How many chickens did he have at first?
Level 3
Harold has 348 lollipops and Eli has 712 lollipops. How many lollipops must Eli give to Harold so that Harold will have thrice as many lollipops as Eli?
Level 3
David has 42 stamps more than Bata. Cali has 20 stamps fewer than Bala. The three children have 109 stamps altogether. How many stamps does Cali have?