Billy had some pastries.
37 of them were macarons. The rest were biscuits. He sold
25 of the macarons and 3 biscuits. In the end, he had 171 pastries left. How many pastries did he sell?
| |
Macarons |
Biscuits |
Comparing pastries
at first |
3x5 =
15 u |
4x5 =
20 u |
Before
|
5x3 =
15 u |
20 u |
Change
|
- 2x3 =
- 6 u |
- 3 |
After
|
3x3 =
9 u |
20 u - 3 |
The number of macarons at first is repeated. Make the number of macarons at first the same. LCM of 3 and 5 is 15.
Total number of pastries left
= 9 u + 20 u - 3
= 29 u - 3
29 u - 3 = 171
29 u = 171 + 3
29 u = 174
1 u = 174 ÷ 29 = 6
Number of pastries that Billy sold
= 6 u + 3
= 6 x 6 + 3
= 36 + 3
= 39
Answer(s): 39
