Answer:
7 : 5
Step-by-step explanation:
let the age of the younger be x , then the older is x + 18, thus
x + x + 18 = 108, that is
2x + 18 = 108 ( subtract 18 from both sides )
2x = 90 ( divide both sides by 2 )
x = 45
Thus younger is 45 and older is 45 + 18 = 63
ratio older : younger = 63 : 45 = 7 : 5