Mike has a sports collection . He has four basketballs, five volleyballs and four soccer balls. He has seven tennis rackets and eight tennis balls. He has eight ping-pong bats and nine ping-pong balls, too. Mike has some bags in his room: four yellow bags and two green bags. He puts   the basketballs in a yellow bag, the volleyballs in a yellow bag, and the soccer balls in a yellow bag. He puts the tennis rackets in a yellow bag, the ping-pong bats in a green bag, and the tennis balls and the ping-pong balls in the last bag. Mike has   _   volleyballs.
four five six seven