Sean has 90% as many beads as Brandon. If Sean gives away 50% of the beads and Brandon gives away 70% of his beads, they will have 180 beads altogether. How many beads do the two of them have?
| |
Sean |
Brandon |
Total |
Comparing Sean
and Brandon at first |
9x2 =
18 u |
10x2 =
20 u |
|
| Before |
2x9 =
18 u |
10x2 =
20 u |
|
| Change |
- 1x9 =
- 9 u |
- 7x2 =
- 14 u |
|
| After |
1x9 =
9 u |
3x2 =
6 u |
180 |
90% =
90100 =
910 50% =
50100 =
12 70% =
70100 =
710 The number of beads that Sean has at first is repeated. Make the number of beads that Sean has the same. LCM of 9 and 2 is 18 u.
The number of beads that Brandon has at first is repeated. Make the number of beads that Brandon has the same. LCM of 10 and 10 is 20 u.
Number of beads in the end
= 9 u + 6 u
= 15 u
15 u = 180
1 u = 180 ÷ 15 = 12
Total number of beads that the two of them have
= 18 u + 20 u
= 38 u
= 38 x 12
= 456
Answer(s): 456
