2 / 5 to 3 / 10 is x to 5 / 6. How to calculate the steps? For example, 3 / 5 is 5 / 6

2 / 5 to 3 / 10 is x to 5 / 6. How to calculate the steps? For example, 3 / 5 is 5 / 6

Proportion is actually division
For example, a: B = C: D, which is actually a / b = C / D, can be calculated according to the multiplication and division method, for example, C = (A / b) * D
Therefore, x = (2 / 5) / (3 / 10) * (5 / 6) = 10 / 9