Adam has 54 red beads.
He has 6 times as many red beads as blue beads.
After he buys an equal number of red and blue beads,
the number of red beads is 4 times that of the blue beads.
- How many red beads are there in the end?
- How many blue beads are there in the end?
- How many beads are there in the end?
- How many beads does Adam buy?
|
Red beads |
Blue beads |
Difference |
Before |
6 x 3 = 18 u |
1 x 3 = 3 u |
5 x 3 = 15 u |
Change |
+ ? |
+ ? |
|
After |
4 x 5 = 20 u |
1 x 5 = 5 u |
3 x 5 = 15 u |
(a)
The difference in the number between the red and blue beads at first and in the end remains unchanged.
LCM of 5 and 3 is 15.
18 u = 54
1 u = 54 ÷ 18 = 3
Number of red beads in the end
= 20 u
= 20 x 3
= 60
(b)
Number of blue beads in the end
= 5 u
= 5 x 3
= 15
(c)
Total number of beads in the end
= 60 + 15
= 75
(d)
Total number of beads that Adam buys
= (20 u - 18 u) x 2
= 2 u x 2
= 4 u
= 4 x 3
= 12
Answer(s): (a) 60; (b) 15; (c) 75; (d) 12