Why do we preferably have round manhole covers and not square ones?

There are 2 cops parked along a one-way street looking for traffic violations. They spot a taxi driver going in the wrong direction, yet they do nothing.

Why?

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

Can you count the number of triangles in the given picture?

After undergoing a successful eye operation, A blind girl has just boarded a train to her home. The doctor asked her to open the bandages after 3 hours. On her train journey, she opened the bandages and within a fraction of the time she commits suicide by jumping off the train.

Though her operation was successful, Why did she commit suicide?

I am thinking of a five-digit number such that:
The first and last digits are the same, their submission is an even number and multiplication is an odd number and is equal to the fourth number. Subtract five from it and we obtain the second number. Then divide into exact halves and we get the 3rd number.

What number I am thinking of?

Replace the question mark with the correct number in below Picture:

I have Rs.50 and I spend it in the way as below.

Why is it very easy to weigh a fish?

If 1+9+8=1, what is 2+8+9?