12. The ratio of the total surface area to curved surface area of a cylinder, whose radius is 40 cm and
height is 20 cm, is:
a. 3:1
b. 2:1
C. 4:1
d. 5:1
Answers
Answer:
c
Step-by-step explanation:
i think c will be your answer !
Answer:
(1) 3:1 is the required answer
Step-by-step explanation:
Solution:-
Firstly we calculate the Total Surface Area of the cylinder .
Using Formula to calculate the TSA of Cylinder.
• Total Surface Area = 2πr(r+h)
→ Total Surface Area = 2×22/7× 40 (40+20)
→ Total Surface Area = 44/7 × 40(60)
→ Total Surface Area = 44/7 × 2400
→ Total Surface Area = 2400×44/7 cm²
- Hence, Total Surface Area of Cylinder = 105600/7
Now, Calculating the Curved Surface Area of Cylinder.
Using Formula
• Curved Surface Area = 2πrh
→ Curved Surface Area = 2×22/7 × 40×20
→ Curved Surface Area = 44/7 × 800
→ Curved Surface Area = 35200/7 cm²
- Hence, Curved Surface Area of Cylinder = 35200/7cm²
Ratio of TSA of Cylinder to CSA Of Cylinder
→ Ratio = TSA/CSA
→ Ratio = 105600/7/35200/7
→ Ratio = 105600/35200
→ Ratio = 3/1 = 3:1
- Hence, the Ratio of TSA of Cylinder to CSA of Cylinder is 3 :1
Hence, the required answer is option (1) 3:1 .