Math Riddles Case 11-20

One thing that I mostly glad for when graduated from college was that I thought I never had to dealt with math anymore. Who'll guess that even as a blogger I still have to work with numbers and equations? Well, at least my position here is the one who give the problems, and you're the one who should think about the solutions.

Enjoy the next ten math puzzles here, which are slightly harder than the previous math riddles.



Math Riddle Case 011

What digit is the most frequent between the numbers 1 and 1,000 (inclusive)? And what digit is the less frequent one?

Answer:

1 is the most frequent one (only has a single extra occurrence because we're including 1000).
0 is the less frequent one. Although there are 3 zeros in 1000, 0 doesn't have any equivalents to 22, 33, 44, 222, 3333, etc.

Math Riddle Case 012

An apple costs half a dollar while a pear costs a dollar. Rick at first bought an apple, then he thought: "I already paid half a dollar, and I have an apple that is also worth half a dollar. So if I give the apple to the shopkeeper, he would overall receive a dollar from me. That should be enough to get me a pear." Is Rick right?

Answer:

No, Rick paid half a dollar for the APPLE. So, if he returns the apple, he should only get his half a dollar back, not a PEAR that costs a dollar.

Math Riddle Case 013

Why should you never mention the number 288 in front of anyone?

Answer:

Because it is too gross (2 x 144 - two gross).

Math Riddle Case 014

How can half of 12 be 7?

Answer:

Cut XII into two halves horizontally. You get VII on the top half.

Math Riddle Case 015

Divide 110 into two parts so that one will be 150 percent of the other. What are the 2 numbers?

Answer:

44 and 66

Math Riddle Case 016

Can you find four consecutive prime numbers that add up to 220?

Answer:

47 + 53 + 59 + 61 = 220

Math Riddle Case 017

Amy took a test that had 20 questions. The total grade was computed by awarding 10 points for each correct answer and deducting 5 points for each incorrect answer. Amy answered all 20 questions and received a score of 125. How many wrong answers did she have?

Answer:

5. She had five wrong answers. If Amy had answered all 20 questions correctly, she would have scored 200. Since she only scored 125, she must have lost 75 points. Since each incorrect answer results in a total loss of 15 points (10 for not getting it correct and 5 for answering incorrectly) she must have missed 5 questions. 5 x 15 = 75, 200 - 75 = 125.

Math Riddle Case 018

You have a cake which you must cut into 8 equal pieces. You may make only 3 cuts. How will do this?

Answer:

Make the first two cuts like an X from the top of the cake. Now slice the cake horizontally - thus getting 8 equal pieces.

Math Riddle Case 019

A large truck is crossing a bridge 1 mile long. The bridge can only hold 14000 lbs, which is the exact weight of the truck. The truck makes it half way across the bridge and stops. A bird lands on the truck. Does the bridge collapse? Give a reason.

Answer:

No it does not collapse. Because it has driven a half mile - you would subtract the gas used from the total weight of the truck.

Math Riddle Case 020

Find a simple method of solving:
6751X + 3249Y = 26751
3249X + 6751Y = 23249

Answer:

Add the equation to give: 10000X + 10000Y = 50000
Divide by 10000 to give: X + Y = 5
Subtract to give: 3502X - 3502Y = 3502
Divide by 3502 to give: X - Y = 1
Therefore: X = 3 and Y = 2

So, that's it about this time hard math riddles. I hope you enjoy it!

Difficulty:

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