question_answer

If the cost of grass plantation is Rs. 5 per square metre, what will be the cost of planting grass in a 2 m wide strip along the boundary of a lawn 20 m long and 15m wide?

A) Rs. 1400                       

B) Rs. 780

C) Rs. 620             

D) Rs. 1500

Correct Answer: C

Solution :

Required cost\[=[120\times 15-16\times 11]\times 5\] \[=[300-176]\times 5\] \[=124\times 5=Rs.\,\,620\]