a jar of 220 marbles is divided equally among a group of marble - players today . if 2 people joined the group in the future , each person would receive 1 marble less . how many people are there in the group today ?
220 = 20 * 11 = 22 * 10 there are 20 people in the group today . the answer is a .
divide(subtract(sqrt(add(multiply(multiply(220, 2), const_4), power(2, 2))), 2), const_2)