A her of 40 horses has 9 white and some black horses. What is the ratio of white to black horses?

The number of white horse to white horse is 9 : 31

Step-by-step explanation:

Given as:

The Total number of horses = 40

The number of white horses = 9

Let the number of black horses = x

So, x + 9 = 40

Or x = 40 - 9 = 31

∴ The number of black horses = 31

Now, The ratio of while to black horses = number of white horse : number of black horse

Or, number of white horse : number of black horse = 9 : 31

Hence The number of white horse to white horse is 9 : 31 Answer