in puzzle hour glass i does not undertand what are the question and i did not what find here
Puzzle Hour Glass
@khemchandrs According to the question, you are given two hour glasses, one of 7 min and and other of 11 minute. You need to check a time span of 15 minutes using these two hourglasses.
So Solution:
Start hourglass 1( of 7 min) and hourglass 2(of 11 min) together. By the time hour glass 1 has completed its span, we have measured 7 minutes and still 11-7= 4 minute is remaining in hourglass 2. Now we invert hour glass 1 again. By the time hour glass 2 completes its span at the 11th minute ,4 minute is stored in hourglass 1. Now again we can invert hourglass 1 and measure more 4 minutes. By this we measured a total of 15 minutes.
Hope this helps 
how many qns can be made out of this topic…?
can we fin out 10mins or 5mins from this as well