Dealing with primes
Probability
Level
2
Lee randomly picks a 2-digit prime number less than . What is the probability that the tens digit is greater than the units digit?
3/121
3/50
3/14
3/11
3/8
This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
1 solution
Primes less than 5 0 are 2 , 3 , 5 , 7 , 1 1 , 1 3 , 1 7 , 1 9 , 2 3 , 2 9 , 3 1 , 3 7 , 4 1 , 4 3 , 4 7 .
Notice there are 1 1 possibilities for the 2-digit prime and because 3 out of the 11 possibilities meet the requirement, thus 1 1 3 is the correct answer.