## Q- An agricultural Co-operative Society of village of Pachla has purchased a tractor. Previously 2400 bighas of land were cultivated by 25 ploughs in 36 days. Now half of the land can be cultivated only by that-tractor in 30 days. Let us calculate by using the theory of variations, the number of plough work equally with one tractor.

Chapter: Variation

## Q- If a ∝ b, b ∝ c let us show that a³b³+b³c³+c³a³ ∝ abc(a³+b³+c³)

Chapter: Variation

## Q- If 15 farmers can cultivate 18 bighas of land in 5 days, let us determine by using theory of variation the number of days required by 10 farmers to cultivate 12 bighas of land.

Chapter: Variation

## Q- Volume of a sphere varies directly with the cube of its radius. Three solid spheres having length of 1 1/2, 2 and 2 ½ meter diameter of the new sphere. [let us consider that the volume of sphere remains same before and after melting]

Chapter: Variation

## Q- Volume of a cylinder is in joint variations with square of the length of radius of base and its height. Ratio of radii of bases of two cylinders is 2 : 3 and ratio of their heights is 5 : 4, let us find the ratio of their volumes.

Chapter: Variation

## Q- If a²+b²∝ ab, let us prove that a+b ∝ a-b

Chapter: Variation

## Q- If x+y ∝ x-y, let us show that– x ³Y ³∝ x³-y³.

Chapter: Variation

## Q- If x+y ∝ x-y, let us show that — x²+y² ∝ xy

Chapter: Variation