Zara baked a total of 320 cookies and shortbreads. After giving away 80% of the shortbreads and 75% of the cookies, she was left with twice as many shortbreads as cookies. Find the number of cookies Zara gave away.
| |
Shortbreads |
Cookies |
| Before |
5x2 =
10 u
|
4 u |
| Change |
- 4x2 =
8 u |
- 3 u |
| After |
1x2 =
2 u |
1 u |
Comparing shortbreads and
cookies in the end |
2x1 =
2 u |
1x1 =
1 u |
80% =
80100 =
4575% =
75100 =
34The number of shortbreads in the end is the repeated identity. Make the number of shortbreads in the end the same. LCM of 1 and 2 is 2.
Total number of pastries at first
= 10 u + 4 u
= 14 u
14 u = 320
1 u = 320 ÷ 14 = 10
Number of cookies that Zara gave away
= 3 u
= 3 x 10
= 30
Answer(s): 30
