Adam has 72 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 2 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 1 = 4 u |
1 x 1 = 1 u |
3 x 1 = 3 u |
Change |
+ ? |
+ ? |
|
After |
2 x 3 = 6 u |
1 x 3 = 3 u |
1 x 3 = 3 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 1 is 3.
4 u = 72
1 u = 72 ÷ 4 = 18
Number of blue beads in the end
= 6 u
= 6 x 18
= 108
(b)
Number of red beads in the end
= 3 u
= 3 x 18
= 54
(c)
Total number of beads in the end
= 108 + 54
= 162
(d)
Total number of beads that Adam buys
= (6 u - 4 u) x 2
= 2 u x 2
= 4 u
= 4 x 18
= 72
Answer(s): (a) 108; (b) 54; (c) 162; (d) 72