Risa, Emma and Tom baked some cookies. Risa and Emma baked
23 of the cookies. Emma and Tom baked
34 of the cookies. Risa and Tom baked 441 cookies altogether.
- What fraction of the cookies did Risa and Tom bake altogether?
- How many cookies did the three girls bake in total?
| Risa |
Emma |
Tom |
Total |
| 2x4 |
1x4 |
3x4 |
| 1x3 |
3x3 |
4x3 |
| 3 u |
5 u |
4 u |
12 u |
(a)
The total number of cookies the same. Make the total number of cookies unchanged. LCM of 3 and 4 is 12.
Number of cookies baked by Emma
= 9 u - 4 u
= 5 u
Number of cookies baked by Risa and Tom
= 3 u + 4 u
= 7 u
Total number of tarts = 12 u
Fraction of the cookies baked by Risa and Tom =
712(b)
Total number of cookies baked by Risa and Tom = 7 u
7 u = 441
1 u = 441 ÷ 7 = 63
Total number of cookies baked
= 12 u
= 12 x 63
= 756
Answer(s): (a)
712; (b) 756
