Penelope's uncle is 8 times as old as her. Penelope will be 7 years old in 3 years' time. In how many years' time will Penelope's age be 60% that of her uncle's?
| |
Penelope's uncle |
Penelope |
Difference |
Before
(now) |
8x2 =
16 u |
1x2 =
2 u |
7x2 =
14 u |
| Change 1 |
+ 3 |
+ 3 |
|
| After 1 |
|
7 |
|
| Change 2 |
+ ? |
+ ? |
|
| After 2 |
5x7 =
35 u |
3x7 =
21 u |
2x7 =
14 u |
60% =
60100 =
35 Penelope's uncle : Penelope = 5 : 3
The difference in age between Penelope's uncle and Penelope always remains the same. Make the difference in age between Penelope's uncle and Penelope the same. LCM of 7 and 2 is 14.
2 u + 3 = 7
2 u = 7 - 3
2 u = 4
1 u = 4 ÷ 2 = 2
Number of years' time when Penelope's age will be 60% that of her uncle's
= 35 u - 35
= 35 x 2 - 35
= 70 - 35
= 35
Answer(s): 35
