Q4 of 43 Page 16

70 trees were planted by Parth and 90 trees were planted by Pradnya on the occasion ofTree Plantation Week. Out of these; 25 trees were planted by both of them together. Howmany trees were planted by Parth or Pradnya?

Given: n(A) = 70, n(B) = 90 and n (A ∩ B) = x = 25

n(A) = number of trees planted by Parth


n(B) = number of trees planted by Pradnya


n (A ∩ B) = number of trees planted by both of them together


n (A ∪ B) = number of trees planted by Parth or Pradnya


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As we know, n (A ∪ B) = n(A) + n(B) - n (A ∩ B)


⇒ n (A ∪ B) = 70 + 90 - 25


⇒ n (A ∪ B) = 160 - 25


⇒ n (A ∪ B) = 35


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