Which ratio is equivalent to 7:3

A : 28 : 12
B : 49 : 9
C : 21 : 7
D : 12 : 8

What is the volume of a cone with a height of 6 cm in the radius of 2 cm

Math it's appreciated. (picture provided)

Cody started biking to the park traveling 15 mph, after some time the bike got a flat so cody walked the rest of the way, traveling 4 mph. if the total trip to the park took 6 hours and it was 46 miles away, how long did cody travel at each speed? solve using rate times time= distance