Question

Mel is 7cm less then her grandma's height. Her brother is 11cm taller then his grandma. Together height total 502 cm. What are their heights?

Answer 1

Mel's height is 159cm, her brother's height is 177cm and their grandma's height is 166cm.

Explanation:

Let the grandma's height be g cm.

Mel's height= (g -7) cm

Brother's height= (g +11) cm

Total height

= Mel's height +brother's height +grandma's height

= g -7 +g +11 +g

= (3g +4) cm

Given that their total heights is 502 cm,

(3g +4) cm= 502 cm

3g +4= 502

3g= 502 -4 (-4 on both sides)

3g= 498

g= 166 (÷3 on both sides)

To find their heights, substitute g= 166 back into the expressions.

Grandma's height= 166cm

Mel's height

= 166 -7

= 159cm

Brother's height

= 166 +11

= 177cm