Question: A city has a population of 300,000. 50,000 people immigrate to the country and then 30,000 people leave. After that 1/8 of the population gets pregnant and 1/4 of those people have twins. How many people are there after the births? Think carefully first, then make a decision:
There was a net immigration to the country of 50,000 - 30,000 = 20,000. So the total number of people before birth is 300,000 + 20,000 = 320,000. That means 320,000 / 8 = 40,000 get pregnant. So 40,000 / 4 = 10,000 have twins. So that means they have 10,000 * 2 = 20,000 children. There are 40,000 - 10,000 = 30,000 children from single births. So the total number of people is 320,000 + 30,000 + 20,000 = 370,000. So the answer is 370000.