UPSC CDS 1 2021 Math Paper

The difference between the outside and the inside surface area of a cylindrical pipe 14 cm long is 44 cm‌2 . The pipe is made of 99 cm‌3 of metal. If R is the outer radius and r is the inner radius of the pipe, then what is (R+r) equal to? (Take‌π=

22

7

)