Make Suppositions (2) - 31 March 2011

1. Old Mac Donald had a farm. On his farm, there were only cows
and chickens which had a total of 41 heads and 100 legs. Find
the number of chickens and the number of cows on his farm.

2. Frank spent $216 on a total of 28 butter cakes. He paid $9 for
each large cake and $5 for each small butter cake. How many
large butter cakes did he buy?

3. Mr Li bought 50 pens and books. Later he decided to exchange
all the books for pens. If he exchanged 1 book for 2 pens, he
would receive 65 pens. How many books did Mr Li buy at first?

4. Mr Li bought 50 pens and books. Later he decided to exchange
all the books for pens. If he exchanged 1 book for 3 pens, he
would receive 80 pens. How many pens did Mr Li buy at first?

5. A transport company is paid $10 for every vase that it delivers
safely and has to pay $2 for every vase that is broken. On one
trip, the company delivered 100 vases and was paid $916. How
many vases were delivered safely.