If k is a positive integer and the tens digit of k+5 is 4, what is the tens digit of k?
1) k '> 35

2) The units digit of k is greater than 5.




The problem statement can be written as :
40 '<=' K+ 5 '<='4935 '<=' K '<='44
Now Tens unit of K can either be 3 or 4 ?
a) k '>' 35.....k can still be 36...39 or 40,41....44. Insuff

b) Units place is '>' 5...This menas can k can only be 35,36,37,38,39. Suff.
Ans : B