Three years ago, Emily`s father was 5times as old as she. If the sum of their present age is 108, find Emily`s present age .
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Emily`s present age = x
Three years ago, Emily`s father age = 5(x - 3)
Emily`s father present age = 5(x - 3) + 3
5(x - 3) + 3 + x = 108
5x - 15 + 3 + x = 108
6x = 120
x = 20
Emily`s present age is 20
Analysing:
The age of Emily's father 3 years ago=5(x-3)
The present age of Emily's father=5(x-3)+3
The present age of Emily's father also equals to (108-x)
Let x years old be Emily's present age
5(x-3)+3=108-x
5x-15+3=108-x
6x=120
x=20
Therefore, Emily's present age is 20 years old.