Even educated parents sometimes find themselves stumped when their young children ask math and science questions — and now a British survey has ranked the 10 queries most feared by moms and dads.

The survey of 2,000 parents with kids between the ages of 5-16 was commissioned by the Big Bang UK Young Scientists and Engineers Fair, which takes place in Birmingham, England from March 15-17.

The findings reveal a quarter of British parents find themselves puzzled by their children’s science and math questions on a daily basis, and half of all parents dreaded not having an answer readily available. One third of parents conduct research to find those answers, but many others said they sometimes make up answers or pass the buck by sending the child to the other parent.

So what are the 10 questions parents fear most?

  1. Why is the moon sometimes out in the day?
  2. Why is the sky blue?
  3. Will we ever discover aliens?
  4. How much does the earth weigh?
  5. How do airplanes stay in the air?
  6. Why is water wet?
  7. How do I do long division?
  8. Where do birds/bees go in winter?
  9. What makes a rainbow?
  10. Why are there different time zones on earth?

[The Big Bang]