What is the number of feet from first base to second base?

88 feet, the same as from home to first.

AnswerThis is a trick question. The distance from point to point is exactly 90 feet, but each bag is 1 foot wide, which means that the distance between them is, in fact, 88 feet.

Each bag is a 15 inch by 15 inch square. First base is entirely inside the infield but second base is centered on the 90 foot point. So 90 feet minus 15 inches minus 7.5 inches = 90 feet minus 22.5 inches or 88 feet 1.5 inches.