BRAIN TEASERS

1 A canoeist paddles up the Liffey and can paddle at 10km/h in still water. However, the Liffey is flowing towards the sea at 5 km/h. The very moment he passes under Butt Bridge, 2.5 km upstream a thoughtless individual at Heuston Bridge throws an empty bottle into the river. How long before the canoeist and the bottle pass?

2 What is three times one fifth of one third of 60 cent?

3 My age is four times what it will be in four years time minus four times what it was three years ago. What’s my age?

4 Billy came second-last in a race and Tommy came second, yet Billy was given the gold medal. Why?

5 I bought 30 birds for €30. If a partridge cost €3, a pigeon costs€2 and a sparrow costs 50c, how many of each birds did I get?