Waves on a particular string travel with a speed of 17 m/s. By what factor should the tension in this string be changed to produce waves with a speed of 102 m/s

Answer 1

That is an increase in wave speed by a factor of
102/17 = 6.00

Since wave speed is proportional to the square root of string tension, T must increase by a factor of
6^2 = 36.