1/8th part of a pencil is black, half of the remaining is white. If the remaining part is blue and length of this blue part is 3^{1}/_{2}cm, then find the length of the pencil ?
6 cm
7 cm
8 cm
9 cm
Correct Option: C
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/16
According to the question, 7L/16 = 3^{1}/_{2} ⇒ 7L/16 = 7/2 ∴ L =8