Answer: He must save for 11 or more weeks. 
Explanation:
Using the inequality, we will solve for x to determine the number. 
130 + 20x > 350 Subtract 130 from both sides 
-130 -130 
 20x > 220 
 x> 11 
Since x is greater than 11, it means that if he saves for 11 weeks, then he will save the exact amount of $350, but since he wants to save more, he must save for 11 or more weeks.