Question

On a page of a telephone directory, there are 300 telephone numbers. The frequency distribution of the digits at the unit's place is given below :

Unit digit	0	1	2	3	4	5	6	7	8	9
Frequency	35	21	28	30	25	14	16	38	38	55

Without looking at the page, a number is chosen at random from the page. What is the probability that the digit at the unit's place of the number chosen is greater than 3 but less than 9?

• A. $\frac{186}{300}$
• B. $\frac{131}{300}$
• C. $\frac{161}{300}$
• D. $\frac{216}{300}$

Answer 1

The correct option is B $\frac{131}{300}$

Total number of frequency distribution of unit digit greater than 3 but less than 9 $=25+14+16+38+38=131$
Total phone no of phone directory $=300$
So the probability of picking unit digit no greater than 3 and less than 9 will be $=\frac{131}{300}$