Lizzy: Roger's age is 5 more than twice Jill's age. In 15 years, their age difference will be 30 years less than Finley's age. If Jill is 20 years old now, how old is Finley?.
Me: Hmmm, let me think. I think this is the detailed solution:
Twice Jill's age is 2 * 20 = 40. If Roger's age is 5 more than twice Jill's age, he is 5 + 40 = 45 years old. In 15 years, Jill will be 20 + 15 = 35 years old. Roger's age will be 45 + 15 = 60 years old in 15 years. The age difference between Roger and Jill in fifteen years will be 60 - 35 = 25 years. In 15 years, the age difference between Roger and Jill will be 30 years less than Finley's age, meaning in fifteen years Finley will be 30 + 25 = 55 years old. Currently, Finley is 55 - 15 = 40 years old. Final answer: 40.