Question : On selling 15 balls for INR 450, there is a loss equal to the cost price of 5 balls. The cost price of a ball is:

Option 1: INR 23

Option 2: INR 54

Option 3: INR 45

Option 4: INR 32

Question : The cost of a notebook increases in proportion to the number of pages in it. A notebook having 100 pages costs INR 20. Find the cost of a notebook having 400 pages.

Option 1: INR 60

Option 2: INR 50

Option 3: INR 80

Option 4: INR 40

Question : Find the volume of a sphere having a diameter of 6 mm, in terms of $\pi$.

Option 1: $12 \pi ~\mathrm{mm}^3$

Option 2: $24 \pi ~\mathrm{mm}^3$

Option 3: $64 \pi~ \mathrm{mm}^3$

Option 4: $36 \pi ~\mathrm{mm}^3$

Question : The side of a square is equal to 40% of the radius of a sphere. If the volume of the sphere is $\frac{500 \pi}{3} \mathrm{~m}^3$, then what is the area of the square?

Option 1: 2 m²

Option 2: 1 m²

Option 3: 9 m²

Option 4: 4 m²

Question : In a camp, there are tents of the same shape and size. Each tent is cylindrical up to a height of 4 m and conical above it. The diameters of the bases of the cylinder and the cone are both 10.5 m and the slant height of the conical part is 10 m. If a total of 3861 m² canvas is used in making all the tents, then how many tents are there in the camp? [ Use $\pi-\frac{22}{7}$ ]

Option 1: 11

Option 2: 7

Option 3: 19

Option 4: 13