Doing Some Calculations

[ivoilic]

Hi I relatively new to PHP and I am having trouble solving this problem:

 

I want to take the number the user has given and then enter it in this equation 100/(2^X).  I can do this easily.  However I also need to apply the same equation to every number less than the given (If the user enters 4 it must by applied to 3,2,1 as well)  I can generate a list of numbers using the range() function:

foreach (range(0, $users_number) as $number) {
    echo $number;
}

  However I can't figure out how to apply the equation to each number.

The next step is to get the total sum but given the values of the the others that's pretty easy.

[scootstah]

How's this?

<?php

$number = 4;

$range = range(1, $number);

$calculated = array();

foreach($range as $r)
{
$calculated[] = 100 / pow(2, $r);
}

echo array_sum($calculated);

[requinix]

Yay math.

 

A for loop can do the individual numbers, and the sum is simply

100 * (1 - 1/2^X)

Hope I didn't just spoil something.

[ivoilic]

Thanks scootstah you solution worked perfectly!