In the morning, Lily made 213 more muffins than Mandy. In the afternoon, Lily made 5/3 as many muffins as she made in the morning and Mandy made 12/7 as many muffins as she made in the morning. In the end, Lily had 323 more muffins than Mandy. How many muffins did Mandy make in the afternoon?
Morning - L = M + 213
Afternoon - L = 5/3 (M + 213)
M = 12/7 * M
M = 12/7 (714)
M = 1224
End L = M + 321
355 + 5/3M = 321 + 12/7M
34 = 1/21M
M = 714
Answer : 1224