Math Riddles

Answer: a nickel and a quarter: one of them isn't a nickel but the other one is

Answer: You have to solve this starting with the last store. This means he walked into the 3rd store with $5, had it doubled to $10 and spent the whole $10. He entered the 3rd store with $5.00. He spent $10, so he had $15 after his money was doubled. $15 / 2= Means he had $7.50 when he entered the 2nd store. He left the 1st store with $7.50. He spent $10 so he had $17.50 after his money was doubled; $17.50 divided by 2. So, he started out with $8.75 when he walked into the first store.

Answer: False. Every year that is exactly divisible by four is a leap year, except for years that are exactly divisible by 100, but these centurial years are leap years if they are exactly divisible by 400. For example, the years 1700, 1800, and 1900 are not leap years, but the years 1600 and 2000 are. So 3 out of every 400 years are not leap years.

Answer: 31

Answer: The gold weighs more.

In avoirdupois weight (feathers are measured in this way), one ounce = 437.5 grains. In troy weight (gold is measured in this way), one ounce = 480 grains.