Question : The ratio of the outer and the inner circumference of a circular path is 5 : 4. If the path is 50 metres wide, then what is the radius of the inner circle?

Option 1: 250 metres

Option 2: 300 metres

Option 3: 200 metres

Option 4: 210 metres

Question : A ball is to be made with an inner radius of 2 units and an outside radius of 3 units. How much material is required to make the ball?

Option 1: $\frac{19}{3} \pi$

Option 2: $19 \pi$

Option 3: $\frac{76}{3} \pi$

Option 4: $\pi$

Question : Identify the correct statement about green algae.

Option 1: Green algae usually have a soft cell wall made of an inner layer of pectose.

Option 2: Green algae usually have a rigid cell wall made of an inner layer of protein and an outer layer of fibre.

Option 3: Green algae usually have a rigid cell wall made of an inner layer of cellulose and an outer layer of pectose.

Option 4: Green algae usually have a rigid cell wall made of an inner layer of fat and an outer layer of protein.

Question : A hemispherical tank full of water is emptied by a pipe at the rate of 7.7 litres per second. How much time (in hours) will it take to empty $\frac{2}{3}$ part of the tank, if the internal radius of the tank is 10.5 m?

Option 1: $\frac{185}{3}$

Option 2: $\frac{185}{6}$

Option 3: $\frac{175}{3}$

Option 4: $\frac{175}{2}$

Question : Two pipes of lengths of 1.5 m and 1.2 m are to be cut into equal pieces without leaving any extra length of pipes. The greatest length of the pipe pieces of the same size that can be cut from these two lengths will be:

Option 1: 0.13 metre

Option 2: 0.4 metre

Option 3: 0.3 metre

Option 4: 0.41 metre