ind the ratio of the curved surfaces of two cylinders of same heights if their radii are in the ratio 1:2?  Select the correct option: A) 18 kmph B) 19 kmph C) 24 kmph D) 17 kmph E) 16 kmph
Total time taken = x/40 + 2x/20 hours   = 5x/40 = x/8 hours   Average speed = 3x/(x/8)   = 24 kmph   Answer: 24 kmph
<result>C</result>
ind the ratio of the curved surfaces of two cylinders of same heights if their radii are in the ratio 1:2?