B. 3
You can find the answer by dividing 22 (number of children) by 10 (number of childer per person of staff). 22÷10=2.2
So, in order to have the licensing standard, you'd have to have 2.2 people. As people are treated as whole numbers you should always round up as by rounding down you'd not be licensed. so, you need 3 staff members for the 22 children. Now that you have the number of staff members that are needed you can divide 22 (number of children) by 3 (number of staff members needed), and this will give you the staff/child ratio for the centre when there are 22 children. 22÷3=7.3 → 1:7.3
