A shopkeeper had 500 eggs. 3/25 of them were broken. 1/5 of the total eggs were kept for guests. How many eggs can be used?

The total number of eggs is 500.
The fraction of broken eggs is $\frac{3}{25}$.
Number of broken eggs $= \frac{3}{25} \times 500$

$$= 3 \times \frac{500}{25}$$ $$= 3 \times 20$$ $$= 60 \text{ eggs}$$

The fraction of eggs for guests is $\frac{1}{5}$ of the total.
Number of eggs for guests $= \frac{1}{5} \times 500$

$$= 100 \text{ eggs}$$

Total unusable eggs = Broken eggs + Eggs for guests

$$= 60 + 100$$ $$= 160 \text{ eggs}$$

Usable eggs = Total eggs - Total unusable eggs

$$= 500 - 160$$ $$= 340 \text{ eggs}$$

The calculated number of usable eggs is 340, which matches option (c).

The final answer is $\text{(c) } 340$.