Mindbender

A: There were the makings of a real fight over the stamps Uncle Fred had sent them. "It's not fair, you've got more than your share," Jill protested. "Give me two and we'll each have the same."

"Not on your life. You're lucky to have what you've got," her brother replied. "Perhaps you should give me two, and then I'd have twice as many as you." That's how it started, but how many stamps had their uncle sent?

B: "Come on," said Susan. "Get back into the car, Mike."

But the boy didn't move. "I'm working out something about those cows," he told her. "There's under a hundred of them. If I got them in fours or fives there'd always be one over, but there'd be one short if I tried sevens."

How many were there?