Adam has 68 blue marbles.
He has 2 times as many blue marbles than red marbles.
After he gives away an equal number of blue and red marbles,
the number of blue marbles is 3 times that of the red marbles.
- How many blue marbles are there in the end?
- How many red marbles are there in the end?
- How many marbles are there in the end?
- How many marbles does Adam give away?
|
Blue marbles |
Red marbles |
Difference |
Before |
2 x 2 = 4 u |
1 x 2 = 2 u |
1 x 2 = 2 u |
Change |
- ? |
- ? |
|
After |
3 x 1 = 3 u |
1 x 1 = 1 u |
2 x 1 = 2 u |
(a)
The difference in the number between the blue and red marbles at first and in the end remains unchanged.
LCM of 1 and 2 is 2.
4 u = 68
1 u = 68 ÷ 4 = 17
Number of blue marbles in the end
= 3 u
= 3 x 17
= 51
(b)
Number of red marbles in the end
= 1 u
= 1 x 17
= 17
(c)
Total number of marbles in the end
= 51 + 17
= 68
(d)
Total number of marbles that Adam gives away
= (4 u - 3 u) x 2
= 1 u x 2
= 2 u
= 2 x 17
= 34
Answer(s): (a) 51; (b) 17; (c) 68; (d) 34