Two numbers are respectively 45% and 20% more than the third. What percentage more is the first to the second?

20.8%

Let the third no. is 100

  I       :      II       :      III

145   :     120     :     100           

  I       :      II

145    :     120

 29     :      24        

ATQ  ⇒  \(\frac{5}{24}\) × 100 = 20.8% (1st no. to the 2nd)