How Many Siblings?
Mary has twice as many brothers as sisters, while her brother John has twice as many sisters as brothers. How many children are there in their family?
ANS: 4 - Mary has 2 brothers and 1 sister, John has 2 sisters and 1 brother!
A rocket blasts off from Earth heading for Mars, getting faster as it travels. In fact, the rocket’s speed doubles every week that it’s in space. If the rocket lands on Mars in week 12, in which week was it halfway there?
ANS: Week 11 - because the rocket's speed doubles each week it had to be halfway to Mars on the week before it landed.
There are 6 teams in a group. Each team plays every other team twice. How many games are there in total?
ANS: 30 games - Give each team a letter and write down all the possible games (eg AvB, AvC, AvD,.. etc) but remember if you have counted AvB, then don't count BvA as this is the same two teams. You should get 15 different pairings. Then double your answer (as each team plays every other team twice).
How Old Is Lucy?
Sarah is three times as old as Peter. Max is twice as old as Peter. Lucy is two years older than Max. Altogether their ages add up to 26 years. How old is Lucy?
ANS: 8 - If Lucy is 8, Max is 6, Peter is 3 and Sarah is 9. Lucy has to be 8 for all the ages to add up to 26.