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
Let the population of village = N Then, adult's population = 5N/8and adult females = 1/2 x 5N/8 = 5N/16 ∴ illiterate females = 4/5 of adult female population ⇒ 400 = 4/5 x 5N/16 ⇒ N = (400 x 16)/4∴ N = 1600
EXAMIANS