Ms. johnson has a box of 60 red and black pens on the shelf. if the ratio of red to black pens is 2 to 3, how many red pens does she have?

Red to Black.
2 to 3.
For every 2 red we have 3 black so
For 4 red we have 6 black and so on..
Notice that
For every 2+3=5 pens we have 2 red ones
If we divide the total number of pens 60 into groups of 5 we will get 60 /5= 12 groups.
12 groups •2 red pens=24 red pens