A) To solve this expression, we need to convert the mixed numbers into improper fractions.

3 2/7 = (3 * 7 + 2)/7 = 23/7
2 1/5 = (2 * 5 + 1)/5 = 11/5

Now we can perform the multiplication and addition:

(23/7) * (11/5) + 1/5

To multiply fractions, we multiply the numerators together and the denominators together:

(23 * 11)/(7 * 5) + 1/5

= 253/35 + 1/5

To add fractions, we need a common denominator. The least common multiple of 35 and 5 is 35, so we can rewrite the fractions with a common denominator:

(253/35) + (1/5) = (253/35) + (7/35)

Now we can add the fractions:

(253 + 7)/35 = 260/35

Simplifying the fraction, we get:

260/35 = 52/7

So the answer to A) is 52/7.

B) To solve this expression, we can perform the multiplication and subtraction:

58 - (2.8 * 6.9)

= 58 - 19.32

= 38.68

So the answer to B) is 38.68.

C) To solve this expression, we can perform the division and subtraction:

85 - (339.94 / 23)

= 85 - 14.78

= 70.22

So the answer to C) is 70.22.