2012 · Q2
A tree increases annually by 1/8th of its height. What will be its height after 2 years, if it stands today 64 cm high ?
General Mental Ability, Quantitative Aptitude and StatisticsNumber system and arithmetic
- A72 cm
- B74 cm
- C81 cm
- D85 cm
Explanation
Each year the height is multiplied by (1 + 1/8) = 9/8, compounded annually. After 2 years the height is 64 × (9/8)². Since (9/8)² = 81/64, this equals 64 × 81/64 = 81 cm. Adding a flat 1/8 each year (64 + 16 = 80 cm) would ignore compounding and is not among the options.