Tina baked a total of 392 cookies and scones. After giving away 80% of the scones and 90% of the cookies, she was left with thrice as many scones as cookies. Find the number of cookies Tina gave away.
| |
Scones |
Cookies |
| Before |
5x3 =
15 u
|
10 u |
| Change |
- 4x3 =
12 u |
- 9 u |
| After |
1x3 =
3 u |
1 u |
Comparing scones and
cookies in the end |
3x1 =
3 u |
1x1 =
1 u |
80% =
80100 =
4590% =
90100 =
910The number of scones in the end is the repeated identity. Make the number of scones in the end the same. LCM of 1 and 3 is 3.
Total number of pastries at first
= 15 u + 10 u
= 25 u
25 u = 392
1 u = 392 ÷ 25 = 7
Number of cookies that Tina gave away
= 9 u
= 9 x 7
= 63
Answer(s): 63
