Answer :
By using the factorial sign ! .
3 + 5 + 7 + 9 + 3! = 30 .
3! means = 1 * 2 * 3 = 6
So he concluded that
3 + 5 + 7 + 9 + 6 = 30.
3 + 5 + 7 + 9 + 3! = 30 .
3! means = 1 * 2 * 3 = 6
So he concluded that
3 + 5 + 7 + 9 + 6 = 30.