4 turtles finish a race. Turtle 1: "I am not second or last." Turtle 2: "I am the best!" Turtle 3: "No one is faster than me." Turtle 4: "I am faster than turtle 2." One of them is lying. Who is it? (Count the turtles from top to bottom.)
Sam is 2 times as old as his sister, Sally. Sam is also half as old as brother, Peter. 5 years later, Sally will be half as old as Peter now. How old is Sam now?
There are 2 yellow marbles and 2 green marbles in a bag. Without looking into the bag, what is the least number of marbles you must take from the bag to get 2 of the same colour?
There are 4 white socks, 4 blue socks and 4 pink socks in a drawer. Jenny is blindfolded and asked to take out some socks from the drawer. How many socks must she take from the drawer so that there is at least one pair of the same colour?