Question

a square wall of length 7m is to be painted find cost of painting at the rate of 80per m^3​

Answer 1

$\bigstar{\sf{\huge{\underline{\red{Given\: :-}}}}}$

Length = 7m

Rate of painting = 80/m²

$\bigstar{\sf{\huge{\underline{\red{Concept\: :-}}}}}$

Portion of the wall to be painted = it's area.

=> area of a square of 7m = portion of the wall required to paint

$\bigstar{\sf{\huge{\underline{\red{Solution\: :-}}}}}$

Area of a square = side²

=> Area of a square of 7m = (7m)²

= 49m²

Now,

Cost of 1 m² of painting = 80

=> cost of 49m² of painting = 80 × 49

= 3920

${\sf{\huge{\fbox{\blue{Cost\: =\: 3920}}}}}$

Answer 2

Answer:

₹ 3920

Step-by-step explanation:

Given :-

Length of the square wall (a) = 7 m.

Find :-

Cost of painting at the rate of ₹ 80 per m².

Now,

Area of a square = a²

                            = (7)²

                            = 49 m²

Cost for 1 m² = ₹ 80

Cost for 49 m² = 80 × 49

                        = 3920

Therefore, the cost for painting the wall of length 7 m is ₹ 3920.