Tina baked a total of 236 biscuits and cookies. After giving away 90% of the cookies and 80% of the biscuits, she was left with five times as many cookies as biscuits. Find the number of biscuits Tina gave away.
| |
Cookies |
Biscuits |
| Before |
10x5 =
50 u
|
5 u |
| Change |
- 9x5 =
45 u |
- 4 u |
| After |
1x5 =
5 u |
1 u |
Comparing cookies and
biscuits in the end |
5x1 =
5 u |
1x1 =
1 u |
90% =
90100 =
91080% =
80100 =
45The number of cookies in the end is the repeated identity. Make the number of cookies in the end the same. LCM of 1 and 5 is 5.
Total number of pastries at first
= 50 u + 5 u
= 55 u
55 u = 236
1 u = 236 ÷ 55 = 7
Number of biscuits that Tina gave away
= 4 u
= 4 x 7
= 28
Answer(s): 28
