31:7

31:7 is a ratio. Ratios represent the proportional relationship between two numbers. In this case, the ratio 31:7 means that the first quantity is 31 times the second quantity. It can be written as:

31/7

To simplify this ratio, you can divide both numbers by their greatest common divisor (GCD). In this case, the GCD of 31 and 7 is 1, so the ratio cannot be simplified any further.