Answer:
180
Step-by-step explanation:
k = 3
v = 60
(Found v by dividing any of the top numbers by the bottom number, ex: 420/7 = 60)
3k = 3(60)
3k = 180
If the diameter is 10.5 then the radius is 5.25.
This is because the radius of a diameter is half the diameter.
So
10.5/2
= 5.25
Therefore the radius is 5.25
Bobby needs to grow at least 1 in to be more than 70 inches tall