Level 2
There are some cows and ducks at a farm. There are thrice as many ducks as cows. The total number of legs from the cows and ducks is 60. How many cows are there?
Level 3
Mr and Mrs Wong took their 3 children to the zoo. An adult ticket cost
2 times as much as a child's ticket. Mr Wong paid a total of $42 for all the tickets.
What was the cost of a child's ticket?
At the souvenir shop in the zoo, Mrs Wong paid $80 for a shirt and 3 caps The shirt cost $35. How much did 1 cap cost?
