ruby - Multiply even-indexed elements of array by 2 and odd-indexed elements of array by 3? -

i have following array contains numbers 1 10:

numbers = [1,2,3,4,5,6,7,8,9,10] 

i want multiply every even-indexed element 2 , every odd-indexed element 3. want array like:

[2,6,6,12,10,18,14,24,18,30] 

i tried following solution:

numbers.select |x|   if x.even?     x * 2   else     x * 3   end   puts x end 

unfortunately, didn't work. have better methods?

looks want every index multiplied 2, , odd indices 3.

this should trick

numbers = [1,2,3,4,5,6,7,8,9,10] numbers.map!.with_index { |n, i| i.even? ? n * 2 : n * 3 } p numbers # => [2,6,6,12,10,18,14,24,18,30] 

as attempt, #select selects elements enumerator wherever result of block true. when want modify enumerator in place, should use #map!. #with_index method available enumerators include index in block.