Adam has 39 blue beads.
He has 3 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 |
3 x 1 = 3 u |
1 x 1 = 1 u |
2 x 1 = 2 u |
Change |
+ ? |
+ ? |
|
After |
2 x 2 = 4 u |
1 x 2 = 2 u |
1 x 2 = 2 u |
(a)
The difference in the number between the blue and red beads at first and in the end remains unchanged.
LCM of 2 and 1 is 2.
3 u = 39
1 u = 39 ÷ 3 = 13
Number of blue beads in the end
= 4 u
= 4 x 13
= 52
(b)
Number of red beads in the end
= 2 u
= 2 x 13
= 26
(c)
Total number of beads in the end
= 52 + 26
= 78
(d)
Total number of beads that Adam buys
= (4 u - 3 u) x 2
= 1 u x 2
= 2 u
= 2 x 13
= 26
Answer(s): (a) 52; (b) 26; (c) 78; (d) 26