Gwen baked a total of 319 biscuits and wafers. After giving away 80% of the wafers and 90% of the biscuits, she was left with four times as many wafers as biscuits. Find the number of biscuits Gwen gave away.
| |
Wafers |
Biscuits |
| Before |
5x4 =
20 u
|
10 u |
| Change |
- 4x4 =
16 u |
- 9 u |
| After |
1x4 =
4 u |
1 u |
Comparing wafers and
biscuits in the end |
4x1 =
4 u |
1x1 =
1 u |
80% =
80100 =
4590% =
90100 =
910The number of wafers in the end is the repeated identity. Make the number of wafers in the end the same. LCM of 1 and 4 is 4.
Total number of pastries at first
= 20 u + 10 u
= 30 u
30 u = 319
1 u = 319 ÷ 30 = 2
Number of biscuits that Gwen gave away
= 9 u
= 9 x 2
= 18
Answer(s): 18
