Question

Bill is 5 years older than Sue is, and the sum of their ages is 67 years. How old is Bill ?

Answer 1

Bill is 36 years old

Explanation:

Let Bill's age be "B" and Sue's age be "S"

Given that Bill is 5 years older than Sue, we can reason that the difference between Bill's and Sue's age must be 5 years, or:

B - S = 5 -----(eq 1)

We are also given that the sum of their ages is 67, or:

B + S = 67 -----(eq 2)

We can solve this system of equations via elimination (by adding the two equations).

(eq 1 ) + (eq2)

(B - S) + (B + S) = 5 + 67

2B = 72

B = 72/2

B = 36 years old

Answer 2

36

Explanation:

x+5=y x - Sue age and y - Bill age

x+y=67

---------

x+x+5=67

2x=62

x=31 - Sue age

---------

y=31+5

y=36 - Bill age