Question

What is the probability of two digits numbers which are multiples of ten ?​

Answer 1

Answer:

Step-by-step explanation:

Counting from 10–99 would be 90 numbers. Out of those numbers we have 10, 15, 20, and son on up to 95. Those are 18 multiples of 5 between these numbers. Now in this case a number is a multiple of 5 if the one’s place is either a 5 or a 0. The ten’s spot can have any number possible (in this case we’ve assume that only 1–9 can be in the ten’s spot.)

So we have:

P(two-digit number is multiple of 5)=(9 C 1)*(2 C 1)/(90 C 1)

=(9 ways to chose numbers 1 to 9 in tens digit* 2 ways to choose either 5 or 0 in ones spot)/(90 possible two-digit numbers)=(9*2)/(90)=18/90=6/30=1/5.