Consider the following information and answer the questions based on it. Out of the 75 birders, 15 wanted to see only sunbird, 10 wanted to see only flycatcher, 12 wanted to see both sunbird and nuthatch, 15 wanted to see only bee-eater, 13 wanted to see both sunbird and bee-eater, 5 wanted to see both flycatcher and nuthatch and the remaining wanted to see only nuthatch. How many birders wanted to see only one bird?

Correct Answer: 45