A car dealer has only red and yellow cars in his show room. He currently has 20% more yellow cars then red. IF he has 20 red cars, how many yellow cars does he have?  Choose the most appropriate option.
A) 25
B) 30
C) 35
D) 40
E) 45
Since we know the dealer only has yellow and red cars in their showroom we can conclude that red and yellow cars make up 100% of the cars. Since we know the difference between the amount of cars is 20% we can assume that the red cars make up 40% of the cars.   20/x=40/100 using cross multiplication we can find that 100x20=2000 and   2000/40= 
<gadget id="calculator">  2000/40</gadget>
<output>50</output>
50   So now we know that there are 50 cars total. We can subtract the number of red cars from the total to find the number of yellow cars. 50-20=30   there are a total of 30 yellow cars. The answer is 30
<result>B</result>
A car dealer has only red and yellow cars in his show room. He currently has 20% more yellow cars then red. IF he has 20 red cars, how many yellow cars does he have?