What is the answer to 3 4/15 + 1 3/10

When you're adding fractions, you've got to find a common denominator.
In this case, 30 is the lowest common multiple. When you're multiplying, you just multiply the fractions and leave out the whole numbers.
You've got to multiply the first fraction by 2, and this becomes 8/30.
You've got to multiply the second fraction, and this becomes 9/30.

You've then got to add these together, and you only add the denominators, so this becomes 17/30. This cannot be simplified further.
Now, you've got to add the two whole numbers.
3+1=4.
Therefore, the answer is 4 17/30
Hope this helps :)