Clark wants to figure how many pens to order for the office there are 36 workers and he needs to order one pen for each worker. He knows that for every three people who prefer red there are nine who prefer blue how many blue pens should he order

Answer 1

red : blue = 3 : 9 = 1 : 3 or x : 3x

x + 3x = 36
x = 9

number of blue = 3x = 27
number of red = x = 9

notice 9+27 = 36 and 9:27 = 3:9 , as stated