There are 20 pens in a package. Ten of the pens are black, 8 are blue, and the rest are red.Which ratio represents the number of red pens to black pens? 110 15 45 51

Answer:1:5Step-by-step explanation:   Their is 2 red pens, because 20(pens) - 8(blue pens) = 12(pens [blue excluded]) and there are 10 black pens (12 - 10 = 2)   So we can get an un-simplified ratio of 2:10, however in the list of answers you gave us:1:101:54:55:1   Their is no 2:10, so now we need to simplify our ratio by dividing both 2 and 10 by 2, 2 divided by 2 = 1 and 10 divided by 2 = 5. As we can now see this gives us the ratio of 1:5 which is our second answer choice, and therefore since 1:5 is equal to 2:10 our answer is 1:5