A lamppost is divided into three parts, the first part is (1/3)rd of the whole length, second (3/8)th of the first and the third is 6 m 50 cm. The length of the lamppost is ?

• A. 14 m
• B. 12 m
• C. 13 m
• D. 11 m

Answer: (B)

Let the length of lamppost = L mThen,first part = L/3and second part = (3/8) x L/3 = L/8 and third part = 6 m 50 cm = 6.50 mFirst part + second part + Third part = length of lamppost ⇒ L/3 + L/8 + 6.5 = L ⇒ L - L/3 - L/8 =6.5 ⇒ (24L - 8L - 3L)/24 = 6.5 ⇒ 13L/24 = 6.5 ∴ L = (65.x 24)/13 = 12 m