Question

The internal and external diameter of a hemispherical bowl are 12 cm and 10 cm respectively. The cost of painting the vessel all over @ Rs 0.07/$c{m}^2$ is

• A. Rs 26.25
• B. Rs 50.52
• C. Rs 25.26
• D. None of the above

Answer 1

The correct option is C Rs 25.26

TSA = $\pi (3R^2+r^2)$
= $\frac{22}{7}(3\times 6^2+5^2)c{m}^2=\frac{22}{7}\times 133c{m}^2$
Cost = Rs $\frac{22}{7}\times 133\times \frac{7}{100}$ = Rs 25.26