A jar of 180 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? Select:
A) 16  B) 18  C) 20  D) 22  E) 24

Rationale: "180 = 18 * 10 = 20 * 9 there are 18 people in the group today . the answer is b ."
Answer: B