Julie had 15 more biscuits than Gem at first. After Julie ate 3 biscuits, she had thrice as many biscuits as Gem in the end. How many biscuits did Gem have?
| |
Gem |
Julie |
| Before |
1 u |
1 u + 15 |
| Change |
|
- 3 |
| After |
1 u |
1 u + 12 |
Comparing Gem
and Julie in the end |
1 u |
3 u |
The number of biscuits that Gem had remains unchanged.
Number of biscuits that Julie had in the end
= 3 x 1 u
= 3 u
3 u = 1 u + 12
3 u - 1 u = 12
2 u = 12
1 u = 12 ÷ 2 = 6
Number of biscuits that Gem had
= 1 u
= 6
Answer(s): 6
