The odds against ram solving the problem are 4 to 5 and the odds in favour of krishna solving the same are 7 to 5. What is the chance that it will be solved when they both try?
Choose the correct choice from the following options:  A) 1/4  B) 5/21  C) 16/21  D) 23/28  E) 22/27
Odds against Ram are 4:5 so probability that he will solve the problem is 5/9.   Odds in favor of Krishna are 7:5 so probability that he will solve it is 7/12   It will be solved means that either Ram or Krishna or both will be able to solve it.   P(A or B) = P(A) + P(B) - P(A and B) = 5/9 + 7/12 - (5/9)*(7/12) = 22/27   22/27
<result>E</result>
The odds against ram solving the problem are 4 to 5 and the odds in favour of krishna solving the same are 7 to 5. What is the chance that it will be solved when they both try?