JAMB Mathematics 2017 Paper

Concept:The capacity of a cylindrical tank is the same as its volume, calculated using $V = \pi r^2 h$.Explanation:The volume is given as $3080\ \mathrm{m}^3$.The diameter of the base is $14\ \mathrm{m}$.So, the radius is $r = \frac{14}{2} = 7\ \mathrm{m}$.Substitute the known values into the volume formula:$$3080 = \frac{22}{7} \times 7^2 \times h$$Since $7^2 = 49$, the base area becomes:$$\frac{22}{7} \times 49 = 154$$Therefore, the equation simplifies to:$$3080 = 154h$$Divide both sides by $154$ to find the depth:$$h = \frac{3080}{154} = 20$$Thus, the depth of the tank is $20\ \mathrm{m}$.Answer:C. 20m