How will you measure 15 minutes using two hourglasses of 7 minutes and 11 minutes respectively?

Look at the picture and find out which square is not linked with any of the other squares.

Using Only Five 5's and any mathematical operator make sum as 37

using four eights (8) and a one (1) and one mathematical symbol , create the number 100

O_er_t_o_

Complete the missing letters of the given word.

Find the next number in the series.
1 10 24 43 67 ?

What is in seasons, seconds, centuries and minutes but not in decades, years or days?

There is a five-letter word which has 3 consonants(all are same) and 2 different vowels.
Also, something wrong is associated with the word.

Can you name it?

A network of 20 x 10 squares is given to you.

Can you calculate how many unique squares and rectangles can be formed combining two or more individual squares ?

You are given a set of weighing scales and 12 marbles. The scales are of the old balance variety. That is, a small dish hangs from each end of a rod that is balanced in the middle. The device enables you to conclude either that the contents of the dishes weigh the same or that the dish that falls lower has heavier contents than the other. The 12 marbles appear to be identical. 11 of them are identical, and one is of a different weight. Your task is to identify the unusual marble and discard it. You are allowed to use the scales three times if you wish, but no more. Note that the unusual marble may be heavier or lighter than the others. You are asked to both identify it and determine whether it is heavy or light