Question 1091343: Imagine you start saving pennies during summer vacation. On the first day, drop one penny into the piggy bank, two pennies the second day, three pennies the third day, and so on. How much money do you have at the end of summer? Vacation this year lasts 75 days.
I would like to know if there is a formula for doing this, since I know that adding each time one by one would take forever.
Found 2 solutions by Boreal, MathTherapy:
Answer by Boreal(15235)   (Show Source):
Answer by MathTherapy(10552)  (Show Source):
You can put this solution on YOUR website!
Imagine you start saving pennies during summer vacation. On the first day, drop one penny into the piggy bank, two pennies the second day, three pennies the third day, and so on. How much money do you have at the end of summer? Vacation this year lasts 75 days.
I would like to know if there is a formula for doing this, since I know that adding each time one by one would take forever.
Yes, there is! You need to use the formula for the sum of an AP, or an Arithmetic Sequence.
This is:  , with:
 = Number of terms (75, in this case)
 = First term (1, in this case)
 = Common difference (1, in this case)
Replacing all these variables should give you 
|
|
|
