SarkariPYQ

SSC Selection Post 2020 PYQ — Question 73

SSC Selection Post - Matriculation Level - 9 Nov 2020 - Shift 3 • Quantitative Aptitude • Q73

Back to paper

The sides of a triangular field are 140 m, 225 m and 265 m. What is the cost of levelling it at ₹5.50 per m2?

Show answer & explanation

Correct answer: D

Explanation

The correct answer is option 4 i.e. ₹86,625.

 

Heron's formula:

Area = s(s−a)(s−b)(s−c)\sqrt{s(s-a)(s-b)(s-c)}

s =  a+b+c2=140+225+2652=6302=315\frac{a + b + c}{2} = \frac{140 + 225 + 265}{2} = \frac{630}{2} = 315  m

Area = 315(315−140)(315−225)(315−265)=315×175×90×50\sqrt{315(315 - 140)(315 - 225)(315 - 265)} = \sqrt{315 \times 175 \times 90 \times 50}

Area =  248,062,500=15,750\sqrt{248,062,500} = 15,750 m2

Cost = Area × Rate = 15,750 × 5.50 = ₹ 86,625