To add these fractions, we need to find a common denominator. The least common multiple of 10, 15, and 6 is 30.

7/10 + 2/15 - 1/6

To convert 7/10 to have a denominator of 30, we multiply the numerator and denominator by 3: (7/10) * (3/3) = 21/30.

To convert 2/15 to have a denominator of 30, we multiply the numerator and denominator by 2: (2/15) * (2/2) = 4/30.

To convert 1/6 to have a denominator of 30, we multiply the numerator and denominator by 5: (1/6) * (5/5) = 5/30.

Now we can add the fractions:

21/30 + 4/30 - 5/30 = (21 + 4 - 5)/30 = 20/30

The fraction 20/30 can be simplified by dividing both the numerator and denominator by their greatest common divisor, which is 10:

20/30 = (20/10) / (30/10) = 2/3

Therefore, 7/10 + 2/15 - 1/6 = 2/3.