Let the probability of student A and B be solving a problem be P (A) = 1/2 and P (B) 3/4 Probability that the problem is solved is :- Probability that at least one will solve is
P(A ∪ B) = P (A) + P (B) – P(A ∩ B)
= P(A) + P(B) – P(A) P(B)
= 1/2 + 3/4 - 1/2 x 3/4
P(A ∪ B) = 0.5 + 0.75 – 0.375
= 0.875.