A right circular cylinder is formed. A = sum of total surface area and the area of the two bases. B = the curved surface area of this cylinder. If A : B = 3 : 2 and the volume of cylinder is 4312 cm3, then what is the sum of area (in cm2 ) of the two bases of this cylinder?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 308
A = 2πr(r+h) + 2πr2
A = 2πr(h+2r)
B = 2πrh
A/B = 2πr(h+2r)/2πrh = 3/2
h+2r/h = 3/2
1 + 2r/h = 3/2
r/h = 1/4
Volume of cylinder = 4312 cm3
22/7 × x × x × 4x = 4312
x3 = 343
x = 7 cm
Area of two Bases = 2 × 22/7 × 7 × 7 = 308 cm2