Question

The length of a rectangle floor is twice its breath. If Rs. 256 is required to paint the floor at the rate of Rs. 2 per sq m, then what would be the length of floor?
(a) 16 m
(b) 8 m
(c) 12 m
(d) 32 m
(e) 20 m

Answer 1

Breadth = x

Lenth = 2x

Area of floor = 256/2 = 128m²

l x b  = 128

2x² = 128

x² = 64

x = 8

Breath = 8m

Length = 16 m

Answer 2

answer : option (a) 16m

explanation : Let breadth of rectangular floor is x and hence, length is 2x.

a/c to question,

256 Rs. is required to paint the floor at the rate of 2 Rs./m²

so, area of rectangular floor = total cost/rate

= 256/2 = 128 m²

but we know, area of rectangle = length × breadth

so, area of rectangular floor = 2x × x

or, 128 = 2x²

or, 64 = x²

or, x = ± 8 but x ≠ -8 because breadth/ length can't be negative.

hence, breadth of rectangular floor = 8m

length of rectangular floor = 16m

hence, option (a) is correct