Tom baked some cupcakes. If he gave each of his friends 5 cupcakes, he would have 25 cupcakes left. If he gave each of his friends 9 cupcakes, he would need to bake another 35 more cupcakes. How many cupcakes did Tom bake?
+197 Tom baked some cupcakes. If he gave each of his friends 5 cupcakes, he would have 25 cupcakes left. If he gave each of his friends 9 cupcakes, he would need to bake another 35 more cupcakes. How many cupcakes did Tom bake?
no. of friends = f, guess the no. of cupcakes
What do you know?
Fixed no. of cupcakes (at first) and friends
| no. of friends | 5 | 10 | 15 |
| 5 * f + 25 | 5 * 5 + 25 = 50 | 5 * 10 + 25 = 75 | 5 * 15 + 25 = 100 |
| 9 * f - 35 | 9 * 5 - 35 = 10 | 9 * 10 - 35 = 55 | 9 * 15 - 35 = 100 |
| no | no | yes |
15 friends
9 - 5 = 4
25 + 35 = 60
60 / 4 = 15 (no. of freinds).
5 * 15 + 25 = 100
9 * 15 - 35 =100
100 cupcakes
