ratio is written in x:y. therefore for this case, red:yellow
5 : 7
since the question states that there are 392 yellow poms, the 7 units represents 392 yellow poms. now you have to gind what is one unit and then multiply by 5 to find the number of red poms.
392 represents 7 units
1 unit: 392/7=56
5 units: 5×56=280 red poms
therefore the answer is 280 red poms which is C.
