The minute hand on an analog clock is 8 inches long. how far does the tip of the minute hand travel in 16 minutes

We know that
on an analog clock
60 minutes is equal to a circumference of 360°
so
360/60> 6°
that means 
1 minute is equal to > 6°
16 minutes> X
x=16*6> 96°

the length of a circumference=2*pi*r
for r=8 in

the length of a circumference=2*pi*8> 50.24 in

if 360° (full circle) has a length of> 50.24 in
  96°> x
x=96*50.24/360> x=13.40 in

the answer is
13.40 in