Find The Next Number in the series:

12 13 15 17 111 113 117 119 123 ?

Find three numbers such that

* When we multiply three numbers, we will get the prime numbers.
* The difference between the second and the first number is equal to the third and second.

A brand new Mobile Phone was on sale at 20% as a promotional offer. By what per cent must the Mobile price be increased to sell it at the original price again?

Decode the below four famous ciphers:

8P of the SS
1M of the E
1S of the SS
60M in 1H

Can you find a five letter word that is left with only two letters if one is removed?

If an electric train is travelling south, then which way is the smoke going?

Make eight squares by moving only two matchsticks.
Note- Square can be of different sizes.

What is the next number in the series?

15 29 56 108 208 ?

What is the centre of gravity?

There are three boxes which are labeled as Rs100, Rs150, and Rs200. One box contains two notes of Rs. 50. The second box contains one note of Rs50 and one note of Rs100 The third box contains two Rs. 100 notes. All boxes are labeled incorrectly.

What is the minimum number of boxes you must check in order to label all boxes correctly?