Adam has 30 blue beads.
He has 5 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 4 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 |
5 x 3 = 15 u |
1 x 3 = 3 u |
4 x 3 = 12 u |
Change |
+ ? |
+ ? |
|
After |
4 x 4 = 16 u |
1 x 4 = 4 u |
3 x 4 = 12 u |
(a)
The difference in the number between the blue and red beads at first and in the end remains unchanged.
LCM of 4 and 3 is 12.
15 u = 30
1 u = 30 ÷ 15 = 2
Number of blue beads in the end
= 16 u
= 16 x 2
= 32
(b)
Number of red beads in the end
= 4 u
= 4 x 2
= 8
(c)
Total number of beads in the end
= 32 + 8
= 40
(d)
Total number of beads that Adam buys
= (16 u - 15 u) x 2
= 1 u x 2
= 2 u
= 2 x 2
= 4
Answer(s): (a) 32; (b) 8; (c) 40; (d) 4