L Let D be a recurring decimal of the form D=0. a1a2a1a2a1a2............; where digits a1 and a2lie between 0 and 9. Further, at most one of them is zero. Which of the following numbers necessarily produces an integer, when multiplied by D? (CAT 2000)
Ans: (c)
D=0. a1a2;100 D=a1a2.a1a2 (recurring); Thus, 99D=a1a2;⇒D=(a1a299)
Required number should thus be a multiple of 99. Hence 198 is the required number.