Answer:
Given:
- Total horses tested = 140
- Horses that had Lyme disease = 42
- Horses that had arthritis = 112
Let x = number of horses that had BOTH Lyme disease and arthritis.
⇒ (112 - x) + (42 - x) + x = 140
⇒ 154 - x = 140
⇒ x = 14
Therefore, place 14 in the middle overlapping area.
To find the number to place in the left section: 42 - 14 = 28
To find the number to place in the right section: 112 - 14 = 98
