A cylindrical vessel open at the top has diameter 28 cm and height 10 cm. The cost of tin-plating it on inside at the rate of ₹50 per 100 cm2, is: (Usе, $π=\frac{22}{7}$)
Answer & explanation
Correct answer: option 1
We have,
A cylindrical vessel open at the top has diameter 28 cm and height 10 cm.
Now the radius = 28/2 = 14 cm
Now the total inside surface area of the vessel = 2πrh + πr2
= 2 × \(\frac{22}{7}\) × 14 × 10 + \(\frac{22}{7}\) × (14)2
= 1496cm2
The cost of tin-plating it on inside at the rate of ₹50 per 100 cm2 = 1496 × 0.5 = 748Rs.