## Math (page 2)These are fun math riddles. All of these tricky riddles are based on real math concepts and can be solved with purely math and logic. These are the tasks listed 11 to 20. |

## Calculate the number 2140

NUMBERMANIA: Calculate the number 2140 using numbers [1, 5, 8, 9, 69, 443] and basic arithmetic operations (+, -, *, /). Each of the numbers can be used only once.**9**

**Rutu Raj**.

## MAGIC SQUARE: Calculate A+B*C

The aim is to place the some numbers from the list (15, 17, 19, 25, 31, 33, 35, 65, 67, 69, 74) into the empty squares and squares marked with A, B an C. Sum of each row and column should be equal. All the numbers of the magic square must be different. Find values for A, B, and C. Solution is A+B*C.**13**

**Sanja Šabović**.

## Find number abc

If a2aa1 - 5cb9c = b1a3 find number abc. Multiple solutions may exist.**21**

**On On Lunarbasil**.

### Special golf ball

Two friends went out to play golf and were about to tee off, when one fellow noticed that his partner had just one golf ball.

“Don't you have at least one other golf ball?” he asked.

The other guy replied that no, he only needed the one.

“Are you sure?” the friend persisted. “What happens if you lose that ball?”

The other guy replied, “This is a very special golf ball. I won't lose it so I don't need another one.”

"Well,” the friend asked, “what happens if you miss your shot and the ball goes in the lake?”

“That's OK,” he replied, “this special golf ball floats. I'll be able to retrieve it.”

“Well what happens if you hit it into the trees and it gets lost among the bushes and shrubs?”

The other guy replied, “That's OK too. You see, this special golf ball has a homing beacon. I'll be able to get it back -- no problem.”

Exasperated, the friend asks, “OK. Let's say our game goes late, the sun goes down, and you hit your ball into a sand trap. What are you going to do then?”

“No problem,” says the other guy, “you see, this ball is florescent. I'll be able to see it in the dark.”

Finally satisfied that he needs only the one golf ball, the friend asks, “Hey, where did you get a golf ball like that anyway?”

The other guy replies, “I found it.”

## Calculate the number 4109

NUMBERMANIA: Calculate the number 4109 using numbers [4, 6, 1, 5, 80, 743] and basic arithmetic operations (+, -, *, /). Each of the numbers can be used only once.**12**

**Manguexa Wagle**.

## Find number abc

If 7b458 - ab8cc = ba58 find number abc. Multiple solutions may exist.**24**

**Thinh Ddh**.

## When I was 10 my brother was...

When I was 10 my brother was half of my age now, I'm 41. How old is my brother now?**72**

**Sanja Šabović**.

## MATH PUZZLE: Can you replace...

MATH PUZZLE: Can you replace the question mark with a number?**50**

**Fazil Hashim**.

## Calculate the number 8379

NUMBERMANIA: Calculate the number 8379 using numbers [7, 9, 8, 4, 94, 948] and basic arithmetic operations (+, -, *, /). Each of the numbers can be used only once.**12**

**Thinh Ddh**.

## MAGIC SQUARE: Calculate A-B*C

The aim is to place the some numbers from the list (3, 4, 5, 7, 8, 9, 55, 56, 57, 58, 85) into the empty squares and squares marked with A, B an C. Sum of each row and column should be equal. All the numbers of the magic square must be different. Find values for A, B, and C. Solution is A-B*C.**14**

**Eugenio G. F. de Kereki**.

## Find number abc

If 40ab9 + 2ab0b = ba97c find number abc. Multiple solutions may exist.**19**

**On On Lunarbasil**.