Set 5questions on joint variation for jss2

Here are 5 questions on joint variation suitable for JSS2:

1. If y varies jointly as x and z, and y = 30 when x = 2 and z = 5, find y when x = 4 and z = 3.

2. The variable a varies jointly as b and c. If a = 48 when b = 3 and c = 4, what is the value of a when b = 5 and c = 6?

3. Suppose p varies jointly as q and r. Given that p = 100 when q = 10 and r = 2, calculate p when q = 5 and r = 8.

4. The amount of work done (W) varies jointly as the number of men (m) and the time spent (t). If 12 men can do 180 units of work in 6 days, how many units of work can 15 men do in 4 days?

5. The volume (V) of a rectangular box varies jointly as its length (l), width (w), and height (h). If a box with dimensions 10 cm × 5 cm × 4 cm has a volume of 200 cm³, find the volume of a box with dimensions 8 cm × 6 cm × 3 cm.