Question

A cistern 6m long and 4 m wide contains water up to a depth of 1 m 25 cm. The total area of the wet surface is:

A) 49 sq.m B) 50 sq.m C) 51 sq.m D) 52 sq.m

Answer 1

Answer:

given: cistern L = 6 m, B = 4 m , H = 1.25 m

to find area of wet surface

area of wet surface = LSA of inner surface upto level of water + area of inner base

=> 2 ( LH + BH ) + LB

=> 2 ( 6 × 1.25 + 4 × 1.25 ) + 6 × 4

=> 2 ( 7.5 + 5 )+ 24

=> 2 ( 12.5 ) + 24

=> 25 + 24

=> 49 cm² option A