PSLE Perry, John and David had 180 stickers altogether. Perry gave
320 of his stickers to John and
14 of his stickers to David. After that, all three boys had the same number of stickers. What was the difference in the number of stickers between John and David at first?
|
Perry |
John |
David |
Total |
Before |
20 u |
9 u |
7 u |
36 u |
Change 1 |
- 3 u |
+ 3 u |
|
|
Change 2 |
- 5 u |
|
+ 5 u |
|
After |
12 u |
12 u |
12 u |
36 u |
Comparing between Perry, John and David in the end |
1x12 = 12 u |
1x12 = 12 u |
1x12 = 12 u |
3x12 = 36 u |
Fraction of stickers that Perry had left
= 1 -
320 -
14 = 1 -
320 -
520 =
1220 Total number of stickers
= 3 x 12 u
= 36 u
36 u = 180
1 u = 180 ÷ 36 = 5
Difference in the number of stickers between John and David at first
= 9 u - 7 u
= 2 u
= 2 x 5
= 10
Answer(s): 10