CPhill

We could have  9 ways to pick the leader x 8 ways to pick the second place rider x 7 ways to pick the third place rider, etc.

So

9 x 8 x 7 x .....x  3 x 2 x 1  = 9!  = 362880  ways to arrange them

[8.5 x 10^10 ]  ÷  [2.3 x 10^7 ]

Notice that this is really the same as this :

[ 8.5 ÷ 2.3 ] x [ 10^10 ÷  10^7 ] = 

[3.6956521739130435] x [ 10^10 / 10^7 ]  

And we have the exponential property that says that, a^n / a^m   =  a^(n - m).....so

10^10 - 10^7  = 10^(10-7)  = 10^3   

So.....we finally have

3.6956521739130435 x 10^3

And that's it  !!!

Correct, BJ.......!!!!!

The answer is given by :

C(7,4) (1/5)^4 (4/5)^3  = 0.028672 = about 2.86%

You can pray sin away......no amount of prayer will remove cos.......

LOL, BJ  !!!!    I love that  !!!!

We'll cope as well as we can.........brains like yours are "rare".......

I think you got one too many zeroes in the second part, Melody.....

The depth is 3.940 x 10³ meters   = 3940m

Sinc there are  100cm to a meter, we have

3940m x 100cm  = 394,000 cm  = 3.940 x 10⁵ cm

I think my answer is good.....I don't know what might be considered "significant"....we're probably looking for a "ballpark" number, anyway.....

This DOES look like one of rosala'a posts....!!!!

I wonder how she's doing???

"Little yellow bus"  isn't exactly the correct terminolgy, here......it's known as  the "Short Bus".....LOL!!!