Question:
I need an equation for the following word problem:

If one cent were placed in an investment that doubles in value every day, what would be the value of the investment at the end of 30 days?

I must keep track of the number of days with the amount of the money.

Day
1	.01
2	.02
3	.04
4	.08
5	.16

ETC. So, I need the baisc formula used for every day! I also need the final formula for 30 days! If you could help me, I would greatly appreciate it!

Thank You,
Holly Hutson
North Carolina

Hi Holly

The key here is to shift the first column down one row.

Day	Day -1	Value
1	0	.01
1	1	.02
1	2	.04
1	3	.08
1	4	.16

and note that 2¹ = 2, 2² = 4, 2³ = 8, ...

Hence the value on a particular day of the month is 2^day-1 cents.

Cheers,
Penny

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