Reading the data questions quickly — and the yes/no statement sets.
Fill the diagram from the inside out: place the most-overlapping region the data fixes first, then work outward, subtracting as you go so each region is counted exactly once. Most errors here are double-counting an overlap, not arithmetic.
Decide whether the events combine with AND (multiply) or OR (add), and convert everything to the same form — all fractions, all decimals or all percentages — before combining. For 'at least one', flip it: 1 minus the probability of none is almost always the faster route.
The five statements are scored together but reasoned separately — judge each one on its own against the data, and do not let a pattern of answers ('surely they can't all be No') override what the numbers say. Read units and totals before judging the first statement; a misread there costs all five.