PHP Taskbook Level 2.5

Задание 1

Given a certain line, for example, like this:

php'023m0df0dfg0'

Get an array of the positions of all zeros in this string.

Задание 2

Given a string:

php'abcdefg'

Remove every third character from this line. In our case, we should get the following:

php'abdeg'

Задание 3

Given some array, for example, like this:

php[1, 2, 3, 4, 5, 6]

Divide the sum of the elements in even positions by the sum of the elements in odd positions.