use of array with random index value in ruby program

# random index value of array in ruby program

def que_ans

q=['What is 8+6?','What is 5*4?','What is 7-4?','What is 3*5?','What is 9/3?']
a=['14','20','3','15','3']

q_len = q.length
a_len = a.length


@que = rand(q_len)

puts "Que:" + q[@que]
c = gets.chomp
if c == a[@que] then
puts "Correct."
else
puts "Wrong! Answer is:" + a[@que]
end

end

puts "Randomly questions from Array:"
for i in  0..4
que_ans
end

OUTPUT:

Randomly questions from Array:
Que:What is 3*5?
3
Wrong! Answer is:15
Que:What is 3*5?
15
Correct.
Que:What is 7-4?
3
Correct.
Que:What is 5*4?
2
Wrong! Answer is:20
Que:What is 8+6?
14
Correct.