Anna and Zara had an equal number of coins at first. Anna used
13 of her coins and Zara used
19 of her coins. They used 36 coins altogether. How many coins did Zara have in the end?
|
Anna |
Zara |
Before |
3x3 = 9 u |
9x1 = 9 u |
Change |
- 1x3 = - 3 u |
- 1x1 = - 1 u |
After |
2x3 = 6 u |
8x1 = 8 u |
The number of coins that Anna and Zara each had at first is the same. Make the number of coins that Anna and Zara each had at first the same. LCM of 3 and 9 is 9.
Number of coins that Anna and Zara used
= 3 u + 1 u
= 4 u
4 u = 36
1 u = 36 ÷ 4 = 9
Number of coins that Zara had in the end
= 8 u
= 8 x 9
= 72
Answer(s): 72