On my sister's 15th birthday, she was 159 cm in height, having grown 6% since the year before. How tall was she the previous year?	Choose the correct choice from the following options:  A) 150 cm  B) 160 cm  C) 170 cm  D) 140 cm  E) 150 cm

Rationale: explanation : given that height on 15 th birthday = 159 cm and growth = 6 % let the previous year height = x then height on 15 th birthday = x × ( 100 + 6 ) / 100 = x × 106 / 100 ⇒ 159 = x × 106 / 100 ⇒ x = 159 × 100 / 106 = 1.5 × 100 = 150 cm answer : option a
Answer: A