Question

Mary’s sister is 7 years older than Mary. Their combined ages add up to 35. How old is Mary

Answer 1

Answer:

Mary - 14

Mary's sister - 21

Step-by-step explanation:

Let x be the age of Mary = x

age of Mary's sister = x + 7

Add up to 35

x + x + 7 = 35

2x = 35 - 7

2x = 28

2x/2 = 28/2

x = 14

Now substitute the value of x

Mary = 14

Mary's sister = 14 + 7 = 21

21 + 14 = 35