Adam has 100 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 6 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 5 = 10 u |
1 x 5 = 5 u |
1 x 5 = 5 u |
Change |
- ? |
- ? |
|
After |
6 x 1 = 6 u |
1 x 1 = 1 u |
5 x 1 = 5 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 5 is 5.
10 u = 100
1 u = 100 ÷ 10 = 10
Number of red marbles in the end
= 6 u
= 6 x 10
= 60
(b)
Number of blue marbles in the end
= 1 u
= 1 x 10
= 10
(c)
Total number of marbles in the end
= 60 + 10
= 70
(d)
Total number of marbles that Adam gives away
= (10 u - 6 u) x 2
= 4 u x 2
= 8 u
= 8 x 10
= 80
Answer(s): (a) 60; (b) 10; (c) 70; (d) 80