Arithmetic Sequence

Question

On Alfredo's 10th birthday, his mother began giving him a weekly allowance of $10 and each week the allowance would increase by $0.50 if he did all his homework. How many weeks would it take for the weekly allowance to become $50 supposing he did all his homework?

Answer 1

Week 1 = $10

Week 2 = $10.50

 

So we know that each week the allowance increases by $0.50 if he does all of his homework, and he starts out with $10 a week. So the allowance has to increase by $40 to get to the total of $50.

 

50 - 10 = 40

 

So now if we divide 40 by 0.50, we will get the total number of weeks needed for his allowance to reach $50:

 

40 / 0.50 = 80

 

(40 divided by a half is the same as multiplying it by 2)

 

So it would take Alfredo 80 weeks to increase his allowance to $50 per week.