The length and breadth of a rectangle are (x + 20) m and (x - 5) m respectively. If its area is 150 m2, find the perimeter of a square whose side is equal to the length of the rectangle.

Find the approximate volume and surface area of a sphere of radius 6 cm. (Use π = 227)

Ram has two spherical balls of radius 10.5 cm each and Meena has six spherical balls of radius 7 cm each. What is the total volume of the balls that Meena has?