A group of 35 students were asked if they owned a laptop or a TV. 10 said they had both. 12 said they had only a TV. 20 said they had atleast a laptop. A student is picked at random. What is the probability that the student has neither a laptop or a TV?

So there are 35 students in total. 10 which have both a laptop and a TV and 12 with only a TV. There are 20 students that own laptops. We have to find out how many students only have laptops. To do this we have to subtract the number of students with both a laptop and tv from the number of students that own laptops, in this case 20. So 20-10=10 students that only own laptops. To find out the probability of the student having neither a laptop nor a TV we subtract the number of students with only a laptop, only a TV and both from the total number of students, in this case 35. So 35-10=25-> 25-12=13->13-10=3. Therefore there are 3 students that have no TV or laptop. To show the probability of no TV or laptop we create a fraction with the 3 students on top over the whole number of students giving us 3/35.