Xandra had 15 more wafers than Usha at first. After Xandra ate 5 wafers, she had thrice as many wafers as Usha in the end. How many wafers did Usha have?
| |
Usha |
Xandra |
| Before |
1 u |
1 u + 15 |
| Change |
|
- 5 |
| After |
1 u |
1 u + 10 |
Comparing Usha
and Xandra in the end |
1 u |
3 u |
The number of wafers that Usha had remains unchanged.
Number of wafers that Xandra had in the end
= 3 x 1 u
= 3 u
3 u = 1 u + 10
3 u - 1 u = 10
2 u = 10
1 u = 10 ÷ 2 = 5
Number of wafers that Usha had
= 1 u
= 5
Answer(s): 5
