In a rectangular field of dimensions 20m x 15m , a triangular park is constructed. If the dimensions of the park are 5m, 7m and 8m respectively, find the cost of levelling the
remaining field at the rate of Rs 100 per m
m?

My answer is 28,250Rs.

Area of a triangle=1/2b×h.

1/2×7×5=17.5.

Area of a rectangle=l×b.

20×15=300.

Area of rectangle-Area of the triangle=300-17.5=282.5m^2.

If 1m^2=100Rs.

then 282.5m^2=282.5×100=28,250Rs.

we can't see all full 4 options, but if this is the full option, than the very left one is correct:

-2/5 * -3 3/4

remake the question, adding a picture of all the question, or write down the full left and right answers.