Martine grew at an average rate of 6cm/year for the first 18 years of her life. If Martine was 50 cm long when she was born, how tall was Martine when she turned 18?

158cm

Step-by-step explanation:

Martine had the height of 50cm when born.

Every year she grows at an average rate of 6cm

So the the first 18 years will be 6cm × 18 = 108cm

She will be 108cm + 50cm = 158cm tall by the time she turns 18 years

50cm + (6 × 18)cm

50cm + (6 × 18)cm50cm + 108cm

50cm + (6 × 18)cm50cm + 108cm158cm

i got 10.28 but that rounds up to 10.3