Question

please find answer of question no 12 who will give me correct explanation wil be brainiest

Answer 1

whenever ratio is given, we have to take Common Factor like x .

Answer 2

The length and breadth are in ratio 2:5
Let common multiple be x
Thus l=2x and b=5x
area of rectangle = l * b
Thus,
5290 = 2x * 5x
5290 = 10x^2
5290/10 = x^2
529 = x^2
x =✓529
x = 23

Therefore
length = 23*2 = 46 m
Breadth = 5*23 = 115 m
Perimeter = 2(l+b)
= 2(46+115)
= 2* 161
= 322m
Cost = 40 per m
total cost = 40*322
= Rs 12,880