By cross multiplication
$$3 \times 10 = 30$$ and $$7 \times 5 = 35$$
Here $$30$$ is smaller than $$35$$
So $$3/5 < 7/10$$
We know that difference between $$7/10$$ and $$3/5$$
$$= 7/10 - 3/5$$
LCM of $$10$$ and $$5$$ is $$10$$
$$= \left(7 \times 1 \right)/\left(10 \times 1 \right) - \left(3 \times 2 \right)/\left(5 \times 2 \right)$$
So we get
$$= \left(7 - 6 \right)/4$$
$$= 1/10$$
Therefore, $$7/10$$ is greater than $$3/5$$ by $$1/10.$$