The curved surface of a cylindrical bulb of height 18 cm and base radius 7 cm is to be painted in luminating gold colour such that 23rd of the height of the bulb emits golden light; painting is done at ₹ 5 per sq. cm. The cost of painting the bulb is Rs _____.(use π=227)2640

The curved surface of a cylindrical bulb of height 18 cm and base radi

1.	The curved surface of a cylindrical bulb of height 18 cm and base radius 7 cm is to be painted in luminating gold colour such that 23rd of the height of the bulb emits golden light; painting is done at ₹ 5 per sq. cm. The cost of painting the bulb is Rs _____.(use π=227)2640
Answer» The curved surface of a cylindrical bulb of height $18 c m$ and base radius $7 c m$ is to be painted in luminating gold colour such that ${\frac{2}{3}}^{r d}$ of the height of the bulb emits golden light; painting is done at ₹ 5 per sq. cm. The cost of painting the bulb is Rs _____. $(u s e π = \frac{22}{7})$ 2640