PSLE At first, a container contained 92 white marbles and some pink beads. After some white marbles were removed,
710 of the marbles were pink. After 75 grey marbles were added to the container and now,
715 of the beads were pink. What was the number of white marbles removed?
|
Pink marbles |
White marbles |
Grey marbles |
Total |
Before |
7 u |
92 |
0 |
|
Change 1 |
|
- ? |
|
+ ? |
After 1 |
7 u |
3 u |
0 |
10 u |
Change 2 |
|
|
+ 75 |
+ 5 u |
After 2 |
7 u |
3 u |
5 u |
15 u |
Some white marbles were removed at first. However, when 75 grey marbles were added, the number of white marbles remains unchanged.
Number of grey marbles added
= 15 u - 10 u
= 5 u
5 u = 75
1 u = 75 ÷ 5 = 15
Number of white marbles removed
= 92 - 3 u
= 92 - 3 x 15
= 92 - 45
= 47
Answer(s): 47