90 pupils were asked whether they owned a laptop or a tablet device. 52 said they owned a laptop. 45 said they owned a tablet. 23 said they owned both. Find the probability that a pupil chosen at ...

Venn diagrams are used to sort sets of data. The probability of an event not happening uses the complement of the region on the Venn diagram. Count the number of elements in each region. Redraw the ...