Answer: 320
Step-by-step explanation:
Let the number of fourth graders be represented by x
Since there are 80 more 3rd graders than 4th graders, the number of 3rd graders will be: x + 80
Since there are 560 3rd and 4th graders. Therefore, this will be:
x + x + 80 = 560
2x + 80 = 560
2x = 560 - 80
2x = 480
x = 480/2
x = 240
4th graders = 240
3rd graders = 240 + 80 = 320
