Given in the question,
If radius is 14 cm then rope can make 70 rounds.
If radius is 1 cm then rope can make 70 x 14 rounds.
If radius is 20 cm then rope can make 70 x 14 / 20 rounds.
If radius is 20 cm then rope can make 7 x 7 rounds.
If radius is 20 cm then rope can make 49 rounds.