A. Lily made $75.36 more than Layla. B. She is incorrect.
A. First find out how many cupcakes each made. To do so, you multiply 8 by 60 to find how many minutes are in those 8 hours, then divide by the number of minutes it took for each batch. Next you'd multiply the answer you get by the number of cupcakes in each batch, to get how many they made total. After that, you find how many each of them sold. Then, you multiply how many they sold, by how much each costed. Finally, you subtract the smaller value from the larger value to find the difference, and who made the most money.
Lily: First, 8*60 = 480. Divide 480 by 10 (how long each batch took) to get 48. Multiply 48 by 7 to get how many cupcakes she made (336). Next, divide 336 by 3, to get 112, then multiply by 2 to find how many she sold (2/3 of 336 = 224). Then, multiply 224 by $1.29 to find how much she made ($288.96).
Layla: First, 8*60 = 480 and divide 480 by 12 (again, how long each batch took) to get 40. Multiply 40 by 8 (cupcakes per batch) to get 320. Divide 320 by 4 to get 80, then multiply 80 by 3 to get how many she sold (240). Multiply $0.89 by 240 to get her total ($213.60). Finally, subtract Layla's total from Lily's total to find out how much more Lily made.
B. Since Layla made 240 cupcakes, and she thinks selling each for a dollar will make her total larger than Lily's, multiply $1.00 by 240, to get $240.00, thus proving her hypothesis was incorrect.