Shiyun baked a total of 447 puffs and tarts. After giving away 90% of the tarts and 80% of the puffs, she was left with thrice as many tarts as puffs. Find the number of puffs Shiyun gave away.
| |
Tarts |
Puffs |
| Before |
10x3 =
30 u
|
5 u |
| Change |
- 9x3 =
27 u |
- 4 u |
| After |
1x3 =
3 u |
1 u |
Comparing tarts and
puffs in the end |
3x1 =
3 u |
1x1 =
1 u |
90% =
90100 =
91080% =
80100 =
45The number of tarts in the end is the repeated identity. Make the number of tarts in the end the same. LCM of 1 and 3 is 3.
Total number of pastries at first
= 30 u + 5 u
= 35 u
35 u = 447
1 u = 447 ÷ 35 = 6
Number of puffs that Shiyun gave away
= 4 u
= 4 x 6
= 24
Answer(s): 24
