Bobby can deadlift 300 pounds at 13.  When he is 18 he can deadlift 100 pounds more than 250% of his previous deadlift.  How many pounds did he add per year?
His new deadlift is 300*2.5+100=<<300*2.5+100=850>>850 pounds
So he added 850-300=<<850-300=550>>550 pounds to his deadlift
This took 18-13=<<18-13=5>>5 years
So he added 550/5=<<550/5=110>>110 pounds per year
#### 110