Question

Bob has one sister.
1. She is 4 years older than twice Bob’s age
2. The sum of their ages is 76


what is the answer?

Answer 1

Answer:

Bob is 36

sister is 40

Step-by-step explanation:

76-4=72

72/2=36

Answer 2

Answer:

sister is 52

bob is 24

Step-by-step explanation:

Let S = sisters age and B = Bob's age

Bob's sister is 4 years older than twice Bob's age:

mathematically : S = 4 + 2B ..... eq1

the sum of their ages is 76

mathematically : S + B = 76 .... eq 2

substituting eq 1 into eq2,

S + B = 76

(4+2B) + B = 76

4 + 3B = 76  (subtract 4 from both sides)

3B = 76 -4

3B = 72  (divide both sides by 3)

B = 72/3 = 24 (answer)

substitute value of B into equation 1

S = 4 + 2B

S = 4 + 2(24)

S = 4 + 48

S = 52 (answer)