Answer:
x = 18
Explanation:
Given:
- 160 total learners
- 34 play soccer and rugby
- 40 play soccer and hockey
- 42 play hockey and rugby
- 36 play soccer only
- 72 play hockey
- 8 play rugby only
- 28 play none of these sports
- x play all three sports
As "x" learners play all three sports, the Venn diagram should have three overlapping circles labelled soccer (S), rugby (R) and hockey (H).
x play all three sports: Label the area that's in S, R and H with x.
8 play rugby only: Label the area that is R only with 8.
36 play soccer only: Label the area that is S only with 36.
28 play none of these sports: Place 28 outside the three circles.
34 play soccer and rugby: Place "34 - x" in the area that's in S and R.
40 play soccer and hockey: Place "40 - x" in the area that's in S and H.
42 play hockey and rugby: Place "42 - x" in the area that's in H and R.
72 play hockey
72 is the total for all the sections of H.
⇒ H = 72 - x - (40 - x) - (42 - x)
⇒ H = 72 - x - 40 + x - 42 + x
⇒ H = x - 10
Place "x - 10" in the area that is H only.
The total number of learners is 160.
Therefore, to find x, sum the areas of the Venn diagram and equal to 160:
⇒ 36 + 8 + 28 + 34 - x + x + 40 - x + 42 - x + x - 10 = 160
⇒ 36 + 8 + 28 + 34 + 40 + 42 - 10 - x + x - x - x + x = 160
⇒ 178 - x = 160
⇒ x = 178 - 160
⇒ x = 18
Finally, substitute x = 18 into the Venn diagram.