Ethan is saving money in his piggy bank for his upcoming trip to disney world. on the first day, he put in $12 and plans to add seven more dollars each day.
part a: write an explicit formula that can be used to find the amount of money saved on any given day.
part b: how much money will he have on the 18th day?
part c: the disney trip is in 187 days from the day he started saving. how much money will he have on the 187th day?

Part A:

Part B: $131

Part C: $1314

Step-by-step explanation:

Ethan is saving money in his piggy bank for his upcoming trip to Disney World. On the first day, he put in $12 and plans to add seven more dollars each day.

Part A:

On the first day, he puts $12 in the piggy bank.

On the second day, he deposited $7 in it. So, after second day he has (12 + 7) = $19.

On the third day, he deposited $7 more in it. So, after third day he has (19 + 7) = $26.

In this way, the savings in the piggy bank are growing in an arithmetic sequence with first term $12 and a common difference $7.

Therefore, the explicit formula that can be used to find the amount of money saved on any given day is given by  

Part B:

Putting n = 18, we get the money that he will have on the 18th day, is given by dollars.

Part C:  

The Disney trip is in 187 days from the day he started saving. Then he will have after 187 days dollars. (Answer)

1. d.90

2. e. none of these (80)

3. a. 0

4. b. 6

5. e. none of these (10)

6. a. 5