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Bill: "When I add 6 times my age 6 years from now to 7 times my age 7 years from now, I get 14 times my current age. How old will I be 5 years from now?" Answer:Answer:90

Solution:

"Let x be my present age. My age 6 years from now will be x + 6, and 6 times that will be 6 (x + 6). Similarly, my age 7 years from now will be x + 7, and 7 times that will be 7 (x + 7).

Adding the two gives 14 times my current age. This gives the equation:

6 (x + 6) + 7 (x + 7) = 14 x.

Solving the above equation gives

x = (6 × 6) + (7 × 7) = 85.

Thus, I will be 90 years old 5 years from now."

Food for thought:

How do you verify the answer?
It's easy! By substitution, right?