Bobby had some pastries.
47 of them were puffs. The rest were tarts. He sold
35 of the puffs and 10 tarts. In the end, he had 105 pastries left. How many pastries did he sell?
| |
Puffs |
Tarts |
Comparing pastries
at first |
4x5 =
20 u |
3x5 =
15 u |
Before
|
5x4 =
20 u |
15 u |
Change
|
- 3x4 =
- 12 u |
- 10 |
After
|
2x4 =
8 u |
15 u - 10 |
The number of puffs at first is repeated. Make the number of puffs at first the same. LCM of 4 and 5 is 20.
Total number of pastries left
= 8 u + 15 u - 10
= 23 u - 10
23 u - 10 = 105
23 u = 105 + 10
23 u = 115
1 u = 115 ÷ 23 = 5
Number of pastries that Bobby sold
= 12 u + 10
= 12 x 5 + 10
= 60 + 10
= 70
Answer(s): 70
