how to detect the place in array ruby code example

Example: ruby find in array

(1..10).detect   { |i| i % 5 == 0 and i % 7 == 0 }   #=> nil
(1..10).find     { |i| i % 5 == 0 and i % 7 == 0 }   #=> nil
(1..100).detect  { |i| i % 5 == 0 and i % 7 == 0 }   #=> 35
(1..100).find    { |i| i % 5 == 0 and i % 7 == 0 }   #=> 35