"Given that he is male" is an important phrase here. The "given" in any probability problem is often important. This tells us "only focus on the males" because we know 100% that whoever we picked, the person is a male.
So we only focus on the "male" column. Use a highlighter to mark this column or cover up the other values if they are too distracting. There are 51 males total (bottom row) and 39 males had a flu shot (top row)
Divide the two values: 39/51 = (13*3)/(17*3) = 13/17
A= 3400t + 600 | given formula 21000= 3400t + 600 | substitute the altitude into the formula 20400 = 3400 | subtract 600 from both sides 6 = t | divide both sides by 3400 6 minutes
