In a survey it was found that 21 people liked product A, 26 liked product B and 29 liked product C. If 14 people liked products A and B, 12 people liked products C and A, 14 people liked products B and C and 8 liked all the three products. Find how many liked product C only.

Question

amistre64 · Answer

venns are good for this, not required, but good nonetheless.

start with the middle and work your way out

amistre64 · Answer

In a survey it was found that:

21 A
26 B
29 C

14 AnB
12 AnC
14 BnC

 8  all the three products

subtract 8 from each of the "ands"

14 - 8: AnB = 6
12 - 8: AnC = 4
14 - 8: BnC = 6

     6
     8
  4    6

subtract the "3 numbers" from each "single" set

21 - (14+4): A = 3
26 - (14+6): B = 6
29 - (14+4): C = 11

amistre64 · Answer

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