9514 1404 393
Answer:
- I know 42 jokes
- My friend knows 21 jokes
Explanation:
The total of the numbers we know individually is more than the total of different jokes we know by the number we both know. That is, adding the number I know and the number my friend knows, I get 60 +3 = 63.
Since I know twice as many as my friend, I know 2/3 of that total, or 42 jokes. My friend knows 1/3 of the total, half the number I know, or 21 jokes.
Then I know 42 -3 = 39 different jokes from my friend. My friend knows 21 -3 = 18 different jokes from me. We know 3 jokes in common, so the total number of jokes we know is 39 +18 +3 = 60 jokes.
I know 42 jokes; my friend knows 21.