The probability is 9/20. Hence the correct option is d.
1. Identifying Favourable Outcomes:
There are 6 multiples of 3 between 1 and 20: 3, 6, 9, 12, 15, 18.
There are 4 multiples of 5 between 1 and 20: 5, 10, 15, 20.
However, we need to adjust for double counting:
Number 15 is a multiple of both 3 and 5, so it has been counted twice in the previous steps.
Therefore, we need to subtract 1 for this double counting: 6 multiples of 3 + 4 multiples of 5 - 1 double count = 9 favourable outcomes.
2. Total Possible Outcomes:
There are 20 tickets (numbered 1 to 20) in total, so there are 20 possible outcomes when drawing one ticket.
3. Calculating Probability:
The probability of drawing a ticket divisible by 3 or 5 is the number of favourable outcomes divided by the total possible outcomes:
Probability = Favourable Outcomes / Total Possible Outcomes
Probability = 9 / 20
Therefore, the probability of drawing a ticket divisible by 3 or 5 is 9/20. Hence the correct option is d.