Math Puzzles - 3 [With Answers]

Puzzle - 1: ( ) + ( ) + ( ) + ( ) + ( ) = 30

This is what you have for equation. The following are the numbers that you can use to fill in the brackets:

1, 3, 5, 7, 9, 11, 13 and 15

You can repeat the numbers if required. The resulting sum should be 30

Answer: There is no mention if you can use sign or not and thus the only possible way to get this is as follows:

(15 - 9) + (13 - 7) + (7 - 1) + (9 - 1) + (13 - 9)

If you solve inside the brackets, you will get the following equation

6 + 6 + 6 + 8 + 4

Adding all these numbers, you will get 30 which is the required sum.

Puzzle - 2: assuming i have an infinite supply of coins.

What is the fewest number of coins would be required in order to make sure each and every coin touched exactly three other coins.

Answer:  Four

Three placed flat on the table in a triangle (touching each other) and put the fourth one on top of them in the middle.

Puzzle - 3:  By using only one straight line, can you make the equation correct.

5+5+5=550?

Answer: Draw a tilted line on 1st plus (+) operator, + will become 4.

The equation then becomes true: 545+5=550.

Puzzle - 4: On a magical-intellectual land of puzzles, all the animal are rational (real smart).

There are six leopards and one sheep. Leopard can eat sheep but since as the land is magical, the leopards who eats the sheep, turns into sheep and then can be eaten by the remaining leopard(s).

If we leave them for some time then how many sheep and leopard will be there, when we come back?

Answer: 5 leopard and one sheep

Since all animal are rational, once 1st leopard eats the sheep all the rest of leopard would know about this.

Puzzle - 5: Which number replaces the question mark?

3 + 5 + 6 = 151872

5 + 5 + 6 = 253094

5 + 6 + 7 = 303585

5 + 5 + 3 = 251573

Then 9 + 4 + 7 =?

Answer: The solution to the first 4 digits is pretty straight forward, and I am sure most of you must have easily got it.

It works out to be a+b+c = (a * b) (a * c)

The last 2 digits are really tough to crack…

Here’s how you do it. Reverse of {(a × b) + (a × c) - c}

So the number would (a × b), (a × c), {(a × b) + (a × c) - c} reverse.

9 + 4 + 7 = 366329