Answer :

Q: If three hens lay three eggs in three days, how many eggs does a (statistical) hen lay in one day?A1: One third. (Note: 3 hens = 3 eggs / 3 days → 3 hens = (3 / 3) (eggs / days) → 1 hen = (1 / 3) (egg / days))A2: Zero or one (it's hard to lay a third of an egg).One can argue about the answers of many brain teasers; in the given example with hens, one might claim that all the eggs in the question were laid in the first day, so the answer would be three.Q: Mary's father has five daughters: 1. Nana, 2. Nene, 3. Nini, 4. Nono. What is the name of the fifth daughter?A: Mary. The first four daughters all have names with the first 4 vowels, so if someone does not think about the question, they may say the name with the fifth vowel, Nunu. The answer was given at the beginning of the question (ie.Mary's fatherhas five...)
you can have them by seaching online NCERT maths book class 7 or 8 last pages many of them