Adam has 40 blue beads.
He has 4 times as many blue beads as red beads.
After he buys an equal number of blue and red beads,
the number of blue beads is 3 times that of the red beads.
- How many blue beads are there in the end?
- How many red beads are there in the end?
- How many beads are there in the end?
- How many beads does Adam buy?
|
Blue beads |
Red beads |
Difference |
Before |
4 x 2 = 8 u |
1 x 2 = 2 u |
3 x 2 = 6 u |
Change |
+ ? |
+ ? |
|
After |
3 x 3 = 9 u |
1 x 3 = 3 u |
2 x 3 = 6 u |
(a)
The difference in the number between the blue and red beads at first and in the end remains unchanged.
LCM of 3 and 2 is 6.
8 u = 40
1 u = 40 ÷ 8 = 5
Number of blue beads in the end
= 9 u
= 9 x 5
= 45
(b)
Number of red beads in the end
= 3 u
= 3 x 5
= 15
(c)
Total number of beads in the end
= 45 + 15
= 60
(d)
Total number of beads that Adam buys
= (9 u - 8 u) x 2
= 1 u x 2
= 2 u
= 2 x 5
= 10
Answer(s): (a) 45; (b) 15; (c) 60; (d) 10