basics.rb

#----------------------------------------------------------------------------------------------------------------------------------
# 
# 														Question 1
# If we list all the natural numbers below 10 that are multiples of 3 or 5, we get 3, 5, 6 and 9. The sum of these multiples is 23.

# Find the sum of all the multiples of 3 or 5 below 1000.


def three_five(number)

	sum = 0
	threes = Array.new
	fives = Array.new 

	for x in (1...number)
		threes.push(x) if x%3 == 0
		fives.push(x) if x%5 == 0
		
	end
	
	threes.each {|t| fives.push(t) if !fives.include?(t)}
	fives.each {|f| sum += f}
	puts sum

end

#three_five(1000)	
#---------------------------------------------------------------------------------------------------------------------------------
# 																	Question 2
# =>  													
#Each new term in the Fibonacci sequence is generated by adding the previous two terms. By starting with 1 and 2, the first 10 terms will be:
#  1, 2, 3, 5, 8, 13, 21, 34, 55, 89, ...
#
# By considering the terms in the Fibonacci sequence whose values do not exceed four million, find the sum of the even-valued terms.

def Fibonacci_max()
	s = [1,1]
	puts s
	x = s.last
	even_sum = 0
	while x < 4000000 
		c = s.count
		n = s[c-2]+s[c-1]
		s.push(n)
		even_sum = even_sum + n if n%2 == 0
		x = s.last
	end	
	s.delete(s.last)
	puts even_sum

end	

Fibonacci_max()