Jaslyn bought thrice as many cookies as Zane. After Jaslyn ate 3 cookies, she had 7 more cookies than Zane. How many cookies did they buy altogether?
| |
Jaslyn |
Zane |
Total |
| Before |
3 u |
1 u |
4 u |
| Change |
- 3 |
|
|
| After |
3 u - 3 |
1 u |
|
The number of cookies that Zane had remains unchanged.
If Zane had another 7 cookies in the end, the number of cookies that Jaslyn and Zane had would be the same.
3 u - 3 = 1 u + 7
3 u - 1 u = 7 + 3
2 u = 10
1 u = 10 ÷ 2 = 5
Total number of cookies
= 3 u + 1 u
= 4 u
= 4 x 5
= 20
Answer(s): 20
