Math Problem for my nice some body help me please?

15 robins. 3 times as many robins as cardinals. so you have a total of 3 units for robins, and 1 unit for cardinals. So there are a total of 4 units. Hence, 20 divided by 4 would be 5. You are asked to find how many robins there were. There were 3 units of robins. Each unit is 5. So 5 multiplied by 3 is 15. I hope that helps. The units part might be a little confusing. Just imagine. If you have 1 ice cream, and your friend has 3 times as many, then your friend would have 3 ice creams. In total, both of you would have 4 ice creams. If those 4 ice creams are equal to 20 candies. How many candies would your friend have?

you need to create two equations and two unknowns.

Let R represent the number of robins and

Let C represent the number of cardinals

Equation One: we get from the sentence "Three times as many robins as cardinals visited a bird feeder" which translates into the math equation: R = 3C

Equation Two: we get from the sentence " a total of 20 robins and cardinals visited the feeder" which translates into the math equation: R + C = 20

Now to solve, substitute R = 3C into R+C = 20 to obtain:

(3C) + C = 20

4C = 20

C = 20/4 = 5

Substitute C = 5 into R = 3C = 3(5) = 15

Therefore there were 15 Robins at the bird feeder.

hope this helps!

i got 6 cardinals and 18 robins. i figure that since there are 20 birds in all, if u take what times 3 plus that number equals 20? so 6 times 3 equals 18 plus 6 equals 20!