Adam has 18 red marbles.
He has 2 times as many red marbles than blue marbles.
After he gives away an equal number of red and blue marbles,
the number of red marbles is 4 times that of the blue marbles.
- How many red marbles are there in the end?
- How many blue marbles are there in the end?
- How many marbles are there in the end?
- How many marbles does Adam give away?
|
Red marbles |
Blue marbles |
Difference |
Before |
2 x 3 = 6 u |
1 x 3 = 3 u |
1 x 3 = 3 u |
Change |
- ? |
- ? |
|
After |
4 x 1 = 4 u |
1 x 1 = 1 u |
3 x 1 = 3 u |
(a)
The difference in the number between the red and blue marbles at first and in the end remains unchanged.
LCM of 1 and 3 is 3.
6 u = 18
1 u = 18 ÷ 6 = 3
Number of red marbles in the end
= 4 u
= 4 x 3
= 12
(b)
Number of blue marbles in the end
= 1 u
= 1 x 3
= 3
(c)
Total number of marbles in the end
= 12 + 3
= 15
(d)
Total number of marbles that Adam gives away
= (6 u - 4 u) x 2
= 2 u x 2
= 4 u
= 4 x 3
= 12
Answer(s): (a) 12; (b) 3; (c) 15; (d) 12