Ok here it is:
Mary's parents decide to give her an allowance every Saturday. The first Sat. they gave her 1cent. For each successive week, they double the amount given the previous week. If Mary saves her allowances, in how many weeks will she be a millionaire?
We can't figure it out! LOL Thankx
2007-02-08 13:03:49 · 5 answers · asked by Anonymous in Education & Reference ➔ Primary & Secondary Education
$1,000,000.00 is 100,000,000 cents
One week = 1c
two weeks = 1+2 = 3c; 2^2 = 4
3 weeks = 1+2+4 = 7c; 2^3 = 8
4 weeks, 1+2+4+8 = 15c, 2^4 = 16
So you see that 2^n where n = number of weeks is always one penny too high
So you need to solve 2^n >= 99,999,999
This can be done with logarithms:
n log 2 >= log 99,999,999
n >= log 99,999,999 divided by log 2
Get a calculator and solve this
2007-02-08 13:09:43 · answer #1 · answered by hayharbr 7 · 3⤊ 0⤋
Sounds like something my math teacher would ask...hehe.
2007-02-08 21:08:34 · answer #2 · answered by the Politics of Pikachu 7 · 0⤊ 0⤋
Half a year?
1,2,4,8,16,32,64,128,256,512,1024,2048,4096,8192,..... then add them together. Should be around 26-27 weeks.
2007-02-08 21:58:52 · answer #3 · answered by Fish Master 5 · 0⤊ 1⤋
Are teachers really this harsh these days?
2007-02-08 21:18:02 · answer #4 · answered by Anonymous · 0⤊ 0⤋
500,000 weeks? lol sorry, i'm not sure
2007-02-08 21:08:43 · answer #5 · answered by Kat 1 · 0⤊ 0⤋