Sloane and Joey are saving up to buy a drone. The cheapest drone they found costs more than $120. They broke open their piggy banks to find
that they already have $48 if they put their money together. They earn $12 a week combined for doing chores around the house. What is the
fewest number of weeks they will have to save their allowance in order to have a combined total of more than $120 to buy a new drone?

So, the question is the number of weeks. What we need to know is in how many weeks exactly are we going to earn more 120 $. The clue given in the question is that,' They earn 12 $ per week.

That can also be written as,

1 week = 12 $

If in one week, we'll earn 12 $ then in how many weeks will we earn more than 120 $ ( Remember, the money should be more than twenty but also the least number which is more than 20.)

So, here we write

1 week= 12 $

2 weeks= 12 × 2 = 24 $

3 weeks= 36 $

4 weeks= 48 $

5 weeks= 60 $

6 weeks= 72 $

7 weeks= 84 $

Now if you wish to verify, you can do the calculations as follows;

84 + 48 = 132$

So, 132 $ is more than 20 and the least number more than 20. Thus, the statement also shows that if it's the least number more than 20, it should also be the least number of weeks.

Hope it helps!