The results of surveying 100 residents of a city reported that 40 read the daily morning paper, 70 read the daily evening paper & 20 read neither. How many:
1. Read at least 1 paper?
2. Read both?
3. Read exactly one daily paper?

Question

The results of surveying 100 residents of a city reported that 40 read the daily morning paper, 70 read the daily evening paper & 20 read neither. How many:
1. Read at least 1 paper?
2. Read both?
3. Read exactly one daily paper?

anonymous · Answer

1. 100-20 (it's stated that 20 read neither, that means they don't read one paper at all)

anonymous · Answer

After solving for 1, then can you solve for 2.

anonymous · Answer

2. (70+40-(100-20))/2 (total of people reading daily morning and daily evening minus the amount of people reading newspapers divided by two because they are the same people.)

anonymous · Answer

3. $$(100-20)-({(70+40)-(100-20) \over 2})$$

anonymous · Answer

Basically, it's the answer from question 1 minus the answer from question 2. (they want to eliminate the number of people who read the paper twice.)

anonymous · Answer

Does this help?