Surface Areas & Volumes | Exercise 13.4 | Q5

NCERT Solutions for Class 9 Math | Curved Surface Area of Hemisphere

Question 5: A hemispherical bowl made of brass has inner diameter 10.5 cm. Find the cost of tin-plating it on the inside at the rate of Rs.16 per 100 cm2.


Target Centum in CBSE 10th Maths


Free Online CBSE Coaching
online.maxtute.com


NCERT Solution to Class 10 Maths


With Videos

Explanatory Answer | Exrecise 13.4 Question 5

Step 1: Compute Curved Surface Area of Bowl

Diameter of the hemispherical bowl, d = 10.5 cm
Radius of the hemispherical bowl, r = \\frac{d}{2}) = \\frac{10.5}{2}) cm
Curved surface area of hemisphere = 2 × π × r2
Take π = \\frac{22}{7})
Curved surface area of the hemispherical bowl = 2 × \\frac{22}{7}) × \\frac{10.5}{2}) × \\frac{10.5}{2})
= 11 × 1.5 × 10.5
= 173.25 cm2

Step 2: Compute the Cost of Tin-plating the Bowl

Cost of tin-plating the hemispherical bowl per 100 cm2 = Rs. 16
Cost of tin-plating the hemispherical bowl per cm2 = Rs. 0.16
Cost of tin-plating the bowl on inside at the rate of Rs.0.16 per cm2= 173.25 × 0.16
= Rs.27.72

 


NCERT Solutions for Class 9 Math | Chapter 13 Video Solutions



WhatsApp: WhatsApp Now
Email: learn@maxtute.com