Fill the Boxes: [] + [] + [] + [] + [] = 30

Here is a tough mathematical puzzle only for the genius. This question came in UPSC Final Exams and only 1 person was able to solve it.


So the difficulty on this riddle is “Very Hard”.

[] + [] + [] + [] + [] = 30

Fill the boxes using one of these numbers 1, 3, 5, 7, 9, 11, 13, 15

You can also repeat the numbers.

So were you able to solve the riddle? Leave your answers in the comment section below.

You can check if your answer is correct by clicking on show answer below. If you get the right answer, please do share the riddle with your friends and family on WhatsApp, Facebook and other social networking sites.

Answer 1:

This is a tough one to crack.

The main issue here is that an addition of odd numbers for odd times will result in an odd number. So in no way will you get an even number like 30 by adding these odd numbers.


So you will have to think out of the box to solve this one.

Use of mathematical operator is a must.

To get an even number from an odd number the best operation to use would be factorial.

So we use 3!,

3! = 3 x 2 x 1 = 6

so if we add 3! five times we get the answer as 30. (As repetition of the number is allowed.)

Hence the answer would be;

3! + 3! + 3! + 3! + 3! = 6 + 6 + 6 + 6 + 6 = 30.

Answer 2:
The answer is
(15 – 9) + (13 – 7) + (7 – 1) + (9 – 1) + (13 – 9)

If you calculate it, you will get

6 + 6 + 6 + 8 + 4 = 30

Exit mobile version