Let the fraction be N.Then, N / (13/14) - (13/14) x N = 3/65⇒ 14N/13 - 13N/14 = 3/65⇒ (196N - 169N)/182 = 3/65⇒ 27N/182 = 3/65∴ N = (3 x 182) / (27 x 65) = 14/45So, correct answer will be (13/14) x (14/45) = 13/45
Let the total length of pencil = L cm Then, black part = L/8∴ Remaining part = L - L/8 = 7L/ 8 and White part = (7L/8)/2 = 7L/8∴ Remaining part = L - (L/8 + 7L/16) = 7L/16∴ length of blue part = 7L/16According to the question, 7L/16 = 31/2⇒ 7L/16 = 7/2 ∴ L =8