Jack speaks the truth in 3/4 the cases and Jill lies in 1/5th cases. What is the
percentage of cases in which both Jack and Jill contradict each other in stating a
fact? (the answers can only be “yes” or “no”).
(a) 60% (b) 35% (c) 20% (d) 15%

• 35%
  
  
  They will contradict in 2 cases
  when
  Jack speaks the truth and Jill lies.
  Jack tells lie the cases and Jill speaks truth.
  
  percentage of such cases = 100*( (3/4 *1/5)+(1/4*4/5))= 100*( 3/20 + 1/5)= 100*7/20 = 35%
• 12 years agoHelpfull: Yes(1) No(1)