Answer is : (c) 60 < p < 65
Let the side of square base of pyramid is x m and height of pyramid is y m.
Volume of pyramid
= 1/3 area of base x height = 1/3 x2y
When x is increased by p%, then new length = x + p% of x = (100+p/100)x
When y is decreased by p%, then new height
= y - p% of y = (100-p/100)y
Now, volume is same.