The sum of the lengths of the radius and the diameter of a circle is 84 cm. What is the difference between the lengths of the circumference and the radius of this circle? [Use π = $\frac{22}{7}$]

148 cm

We know that,

Circumference = 2πr

We have,

Radius + Diameter = 84 cm

Now, according to question, 

R + 2R = 84

= 3R = 84

= R = 28 

So, The circumference = 2πr = 2 × \(\frac{22}{7}\) × 28 = 176 cm

Now, difference between Circumference and radius is = 176 – 28 = 148 cm