To do dis all we need to do is divide the amount of money he needs to spend by d amount of money he has already used. Den d answer will be d amount of dollars more he needs to spend to get a free meal. den we will check our work. Lets do it;- 
 
50 - 30.25 = 19.75 
Tom needs to spend $19.75 more to get a free meal. 
 
CHECK OUR WORK:- 
 19.75 + 30.25 = 50 
 We were RIGHT!! 
 
So, Tom needs to spend $19.75 more to get a free meal. 
 
Hope I helped ya!! xD