At first, Bobby had 30 mochi balls and Ahmad had 6 times as many mochi balls as Bobby. After they each received an equal number of mochi balls from their niece, Ahmad had thrice as many mochi balls as Bobby. How many mochi balls did their niece give to both of them altogether?
| |
Bobby |
Ahmad |
Difference |
| Before |
1x2 =
2 u |
6x2 =
12 u |
5x2 =
10 u |
| Change |
+ 3 u |
+ 3 u |
|
| After |
1x5 =
5 u |
3x5 =
15 u |
2x5 =
10 u |
Since both received an equal number of mochi balls, the difference in the number of mochi balls remains unchanged. LCM of 5 and 2 is 10.
2 u = 30
1 u = 30 ÷ 2 = 15
Number of mochi balls that each received
= 5 u - 2 u
= 3 u
Number of mochi balls that both of them received altogether
= 2 x 3 u
= 6 u
= 6 x 15
= 90
Answer(s): 90
