Test 8 Sec 6 Q 29

In a certain country, a person is born every 3 seconds and a person dies every 10 seconds. Therefore, the birth and death rates account for a population growth rate of one person every.

Can anyone help me with this question? Tried to solve it numerous of times but cannot seem to get the right answer.

By how much does the population increase in 30 seconds? Hint: 10 people are born and 3 die.