Math Riddles

Answer: 7. If you break the batteries into 3 groups: Two groups of 3 and one group of 2. By doing this you guarantee that one of the groups has 2 working batteries. Both of the groups of 3 have 3 possible combinations of 2 batteries and the group of 2 only has 1 combination. So, 3 + 3 + 1 = 7 tries at most to find two working batteries.

Answer: 2. The first page in each book is page number 1 regardless of how they are oriented and 1 + 1 = 2.

Answer: He can propose a plan that he gets 98 pieces of gold, the 3rd pirate gets 1 piece, and the 5th pirate gets 1 as well.

If there were just 2 pirates the younger pirate would definitely deny the plan so he could get all of the gold.

If there were 3 pirates the first pirate can offer the second pirate 1 piece of gold and take the rest himself because the second pirate wouldn't get anything if he has to propose a plan himself.

If there were 4 pirates the first pirate could take 99 for himself and offer 1 to the youngest pirate. They would both agree. If the youngest disagrees then he won't get any gold in the next plan.

So when there are 5 pirates it is in the interest of the 3rd and 5th pirate to accept 1 piece, because if they don't they won't get anything in the next plan.

Answer: 1, the only person that is assumed to be going to St. Ives is the narrator. But the following answers can be found if looking at the question in other ambiguous ways: 2802, 2800, 0, 2, 2753, 7, and 9.

Answer: 7.5 degrees.

The minute hand is pointing directly at the '3'. The hour hand is 1/4 of the way between the '3' and '4'. Since there are 12 numbers the angle between each number is 30 degrees. So the angle between the hands are 30 degrees * 1/4 = 7.5 degrees.