Peter had some pastries.
58 of them were cookies. The rest were tarts. He sold
34 of the cookies and 12 tarts. In the end, he had 56 pastries left. How many pastries did he sell?
| |
Cookies |
Tarts |
Comparing pastries
at first |
5x4 =
20 u |
3x4 =
12 u |
Before
|
4x5 =
20 u |
12 u |
Change
|
- 3x5 =
- 15 u |
- 12 |
After
|
1x5 =
5 u |
12 u - 12 |
The number of cookies at first is repeated. Make the number of cookies at first the same. LCM of 5 and 4 is 20.
Total number of pastries left
= 5 u + 12 u - 12
= 17 u - 12
17 u - 12 = 56
17 u = 56 + 12
17 u = 68
1 u = 68 ÷ 17 = 4
Number of pastries that Peter sold
= 15 u + 12
= 15 x 4 + 12
= 60 + 12
= 72
Answer(s): 72
