If Emma were 3cm taller, she would be twice the height of her brother. He is 75cm tall. How tall is Emma?

Answer 1

Let X be Emma's height.
If Emma were 3 cm taller, she would be X + 3 cm tall.
Twice the height of Emma's brother is 75 cm x 2 = <<75*2=150>>150 cm.
X + 3 = 150 cm
Emma's height, X = 150 cm - 3 cm = <<150-3=147>>147 cm. Answer: \boxed{147}.