Andrew has seven fewer coins than casey. bob has three more than twice as many coins as andrew. altogether, they have 502 coins. how many coins does bob have?

Let C is the number of coins Casey has

Andrew has seven fewer coins than casey = C - 7

Bob has three more than twice as many coins as Andrew = 2 (C-7) + 3

altogether, they have 502 coins = C + (C - 7) + 2 (C-7) + 3 = 502

Now solve for C:

C + (C - 7) + 2 (C-7) + 3 = 502

C + C - 7 + 2C - 14 + 3 = 502

4C - 18 = 502

4C = 502 + 18

4C = 520

C = 520/4

C = 130

So Casey has 130 coins

Andrew: C - 7 = 130 - 7 = 123

Bob: 2 (C-7) + 3 = 2 (130 - 7) + 3 = 2 (123) + 3 = 246 + 3 = 249

Proof: 130 + 123 + 249 = 502

Answer: Bob has 249 coins