Luke's uncle is 3 times as old as him. His uncle will be 34 years old in 7 years' time. In how many years' time will Luke's age be 70% that of his uncle's?
|
Luke's uncle |
Luke |
Difference |
Before (now) |
3x3 = 9 u |
1x3 = 3 u |
2x3 = 6 u |
Change 1 |
+ 7 |
+ 7 |
|
After 1 |
34 |
|
|
Change 2 |
+ ? |
+ ? |
|
After 2 |
10x2 = 20 u |
7x2 = 14 u |
3x2 = 6 u |
70% =
70100 =
710 Luke's uncle : Luke = 10 : 7
The difference in age between Luke's uncle and Luke always remains the same. Make the difference in age between Luke's uncle and Luke the same. LCM of 2 and 3 is 6.
9 u + 7 = 34
9 u = 34 - 7
9 u = 27
1 u = 27 ÷ 9 = 3
Number of years' time when Luke's age will be 70% that of his uncle's
= 20 u - 34
= 20 x 3 - 34
= 60 - 34
= 26
Answer(s): 26