Answer:
<h2>10 inches</h2>
Step-by-step explanation:
Given the circumference= 30 in
we know that the formula for circumference is


The diameter is 2*r= 4.77*2=9.55 in
Approximately the diameter is 10 inches
The given question is 8+13+18+...... which is in arithmetic progression . And for arithmetic series, we have to use the following formula for nth term .

Here a =8 , d=5
So we get

And the required expression for n=7 is
