CPhill

OK.....just use this

1 - (.80)(.90) = .28 = 28%

{Prove this for yourself}

We could have put it at the beginning.....it doesn't matter....

So the formula  is

A= P(1+r)^n x 100%

Let's look at it this way, rosala....

Something costs $1 but you have a 20% discount.....so  20%  of $1 is .20

So far....we would pay ......  $1  - .20   = .80

Now....let's apply the second discount.....this is 10% of .80

And 10% of .80   = .08

So.....this means that we get .08 off of .80  = .80 - .08  = .72

Now, notice that the total discount is .20 + .08 =  .28.......which is just 28% of one dollar

So....we got a total discount of 28%

Does that help??

8 3/8 % = 8.375%  = .08375

So..the amount paid is....

112(.75)(1 - .08375)  =  about $76.97

The pattern appears to be

2(3)^(n-1)    for n = 1, 2, 3, 4.......

So we have

2, 6, 18, 54, 162, 486

Reading the question again.......go with Anonymous' answer......

If you want to use 2 as the log base......type in

" log (a, 2) "   where "a" is the number you're taking the log of in base 2

9 1/4   =  37/4

7 1/2  =   15/2

37/4 - 15/2   =

37/4 / 30/4  =

7/4  lbs left = 1 3/4 lbs.

I used this "formula".........

C(26,5)  = 26! / [ (26 - 5)! (5)! ]

Mine counts all the different sets.....Anonymous' counts total ways......since both words are used in the question.....take your pick....