How do you calculate the 45 to begin with though- I don't understand how it came from the given numbers
You know 100% passed the exam, so that has to be the total of the 3 numbers.
Add the 79 and the 66 together to find out how much the 'overlap' 100 - the answer is 145 ie 45, so put 45 in the overlap area. Then just take 45 from 79 and 45 from 66 to find the numbers in the other parts.
You know 100% passed the exam, so that has to be the total of the 3 numbers.
Add the 79 and the 66 together to find out how much the 'overlap' 100 - the answer is 145 ie 45, so put 45 in the overlap area. Then just take 45 from 79 and 45 from 66 to find the numbers in the other parts.