For how many positive integers x is \log _{10}(x-40)+\log _{10}(60-x)<2 ?
Answer Choices
A. 10
B. 18
C. 19
D. 20
E. infinitely many
For how many positive integers x is \log _{10}(x-40)+\log _{10}(60-x)<2 ?
Answer Choices
A. 10
B. 18
C. 19
D. 20
E. infinitely many