If I remove one from eleven it becomes Ten and if I remove one from nine also becomes Ten. How?

Can you solve this tricky maths equation problem by replacing it? mark with the correct symbol?

19834 -----: 187
15921 -----: 153
17561 -----: 139
13734 -----: ???

Quickly Solve this riddle

7 - 4 + 3 * 0 + 1 = ?

A Scientist was fifty years old in the year 2000 but he was forty years old in the year 2010. How can this be possible?

PS: It has a logical answer.

A man is found hanging dead from the ceiling of a room. The room’s dimensions are 15 x 15 x 15. The man is only 6ft tall and the rope was only 2ft long. There are no windows and only one door to the room. The door is bolted shut from the inside, and a puddle of water is under the man. How did he kill himself?

I left my campsite and hiked south for 3 miles. Then I turned east and hiked for 3 miles. I then turned north and hiked for 3 miles, at which time I came upon a bear inside my tent eating my food! What colour was the bear?

Can you name any English verb that becomes its past tense by simply rearranging the alphabets ?

I am the beginning of everything, the end of everywhere. I'm the beginning of eternity, the end of time and space. What am I?

There were three women in all the swimming costumes!
One was happy and the other two were sad!
The happy one was crying and the sad ones were smiling.
Why was this?

When a clock is observed, the hour hand is at a minute mark and the minutes hand is six minutes ahead of it.

When the clock is observed again after some time, the hour hand is precisely on a different minute mark and the minute hand is seven minutes ahead of it.

Can you calculate how much time has elapsed between the two observations?