Posted by arzam on Thursday, May 2, 2013 at 1:40pm.
There are 90 2-digit numbers
a) 32 are greater than 68, so prob = 32/90
b) 10 are multiples of 9, so ...
c) all are less than 100, so ...
d) 18 have at least one 5, so ...
There are 90 two-digit numbers (10-99).
a) 31/90 = ?
b) 18, 27, 36, 45, 54, 63, 72, 81, 90, 99 are multiples of 9.
c) All two-digit numbers are less than 100.
d) 15, 25, 35, 45, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 65, 75, 85, 95 all have at least one 5.
My bad on (a). PsyDAG is correct
thanks PsyDAG and Steve