Question

Three times as many robinsas cardinals visited a bird feeder. If a total of 20 robin and cardinals visited the feeder, how many were robins

Answer 1

X=# of cardinals
3 times as many robins as cardinals visited the feeder, so # of robins=3x
robins+cardinals=20, so x+3x=20
4x=20
x=5 cardinals
20-x=15 robins