Erika, Yen and John baked some cookies. Erika and Yen baked
23 of the cookies. Yen and John baked
35 of the cookies. Erika and John baked 451 cookies altogether.
- What fraction of the cookies did Erika and John bake altogether?
- How many cookies did the three girls bake in total?
| Erika |
Yen |
John |
Total |
| 2x5 |
1x5 |
3x5 |
| 2x3 |
3x3 |
5x3 |
| 6 u |
4 u |
5 u |
15 u |
(a)
The total number of cookies the same. Make the total number of cookies unchanged. LCM of 3 and 5 is 15.
Number of cookies baked by Yen
= 9 u - 5 u
= 4 u
Number of cookies baked by Erika and John
= 6 u + 5 u
= 11 u
Total number of tarts = 15 u
Fraction of the cookies baked by Erika and John =
1115(b)
Total number of cookies baked by Erika and John = 11 u
11 u = 451
1 u = 451 ÷ 11 = 41
Total number of cookies baked
= 15 u
= 15 x 41
= 615
Answer(s): (a)
1115; (b) 615
