_ + _ + _ + _ + _ = 30. Fill the boxes using (1, 3, 5, 7, 9, 11, 13, 15).

Question
_ + _ + _ + _ + _ = 30

Fill the boxes using (1, 3, 5, 7, 9, 11, 13, 15)
You can also repeat the numbers.

Note : This question came in UPSC Final Exams held in Dec '13.
You will be glad to note that only Gaurav Agarwal could solve it.

Answer
If you can use only '+' sign, then it is never possible. As there are 9 boxes, there will be 5 numbers (in alternate boxes) and 4 signs (in the remaining boxes). Sum of 5 odd numbers can never be even.

But, nothing is impossible. Take a look at the answer below.

3 weeks + 11 hours + 13 hours + 1 day + 7 days = 30 days!


Comments