PSLE At first, a box contained 88 pink marbles and some blue beads. After some pink marbles were removed,
47 of the marbles were blue. After 24 black marbles were added to the box and now,
411 of the beads were blue. What was the number of pink marbles removed?
|
Blue marbles |
Pink marbles |
Black marbles |
Total |
Before |
4 u |
88 |
0 |
|
Change 1 |
|
- ? |
|
+ ? |
After 1 |
4 u |
3 u |
0 |
7 u |
Change 2 |
|
|
+ 24 |
+ 4 u |
After 2 |
4 u |
3 u |
4 u |
11 u |
Some pink marbles were removed at first. However, when 24 black marbles were added, the number of pink marbles remains unchanged.
Number of black marbles added
= 11 u - 7 u
= 4 u
4 u = 24
1 u = 24 ÷ 4 = 6
Number of pink marbles removed
= 88 - 3 u
= 88 - 3 x 6
= 88 - 18
= 70
Answer(s): 70