Good girls and bad boys (8)
On an island, there is this strange pattern - boys always lie while girls always tell the truth. This time round, you encounter four children.
The oldest one says, "At least one of us is a boy."
The second one says, "At least two of us are boys."
The third one says, "At least three of us are boys."
The youngest one says, "All four of us are boys."
Convert the four children to a number based on their order of birth. Then submit your answer as the sum of the numbers of the boys only. For example, if you think only the youngest child is a boy, then your answer is 4. If you think only the middle two children are boys, then your answer is 2+3=5.