To solve this we must first multiply 300*0.40 to find the percentage of yellow balls.
300*0.40=120(0.40=40% in decimal form)
The result is 120 which means that 120 of the balls are yellow.
Again we must find another percentage this time out of the 120 yellow balls.
120*0.20=24
24 balls of the hidden yellow balls were found by the team.
Now we must find how much of the balls were white to find the final result.
The process is simple we subtract 120 form 300 to find the amount of white balls.
300-120=180
180 of the balls were white.
Finally we find the last percentage which is out of the white balls
180*0.80=144
144 white balls were found by the team.
144 white+24 yellow=168 balls in total.
168 balls in total is our final result!
Hope this helps and have a wonderful day!