Sabrina and Mary had an equal number of coins at first. Sabrina used
13 of her coins and Mary used
18 of her coins. They used 77 coins altogether. How many coins did Mary have in the end?
| |
Sabrina |
Mary |
| Before |
3x8 =
24 u |
8x3 =
24 u |
| Change |
- 1x8 =
- 8 u |
- 1x3 =
- 3 u |
| After |
2x8 =
16 u |
7x3 =
21 u |
The number of coins that Sabrina and Mary each had at first is the same. Make the number of coins that Sabrina and Mary each had at first the same. LCM of 3 and 8 is 24.
Number of coins that Sabrina and Mary used
= 8 u + 3 u
= 11 u
11 u = 77
1 u = 77 ÷ 11 = 7
Number of coins that Mary had in the end
= 21 u
= 21 x 7
= 147
Answer(s): 147
