The depth of a water tank of cube size of equal sides is 100cm. If 50 ltr of water is drawn-out of the tank daily, in how many days all the water of the tank be finished?

**A.**2**B.**10**C.**20**D.**200

Answer: **C.** 20

Let’s start by finding the volume of the water tank. Since it’s a cube, the volume (*V*) is given by the formula ** V=side^{3}**.

The depth of the tank is given as 100 cm, so all sides of the cube are also 100 cm.

*V*=100^{3}cm^{3}

Now, convert the volume to liters.

V_{liters} = (100^{3}/1000) liters

(*1 liter is equivalent to 1000 cubic centimeters*)

V_{liters} = 1000000/1000 = 1000 liters

Given that 50 liters of water are drawn out daily

Now, to find out in how many days all the water will be finished, we divide the initial volume by the amount drawn out each day:

V_{liters} /50 = 1000/50 = 20

Therefore, **20 days** it will take for all the water in the tank to be finished.