Sheila went shopping and spent $120 on a coat. she then used 2/3 of the remaining money to buy a dress. she was left with 1/5 of her original amount of money. how much did sheila have at first?

answer: all of the odd numbers were opened

the first person was the one that was opening all of the lockers. since one is odd, this causes all of the odd number lockers to be opened in the end.

cross multiplying, we get :

⇒ (3) × (5) = (9) × (x)

⇒ 15 = 9x