Question

Solve the attachment file.....

Answer 1

${\huge{\bold{\red{Your\:Answer}}}}$....

$\underline\bold{Formula\:used}$

TSA= 2[lb+hl+hl]

TSA=2[bh+hl]+lb

[ we don't White wash at floor so we have to remove 1 lb ]

TSA= 2[12+15]+20.

TSA= [24+30]+20.

TSA= 54 +20.

TSA= 74.

7.50 × 74
= 555

Answer 2

$\mathcal{Given:}$

Length = 5 m
Breadth = 4 m
Height = 3 m
Rate of white washing = Rs. 7.50 per m^2

$\mathcal{To find:}$

Cost of white washing the room = ?

$\mathcal{Solution:}$

TSA = 2 (lb+bh+hl)

TSA = 2 [(5 × 4)+(4 × 3)+(3 × 5)]

= 2 × (20+12+15)

= 2 × 47

= 94 m^2

Since we do not white wash the floor, we will subtract it from the TSA.

= TSA-(l×b)

= 94 - (5×4)

= 94 - 20

= 74 m^2

Cost of white washing the walls of the room = 74 × 7.50

= Rs. 555