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.

You can see three almost identical images below. Can you spot the odd one out from them?

You have $100 with you and you have to buy 100 balls with it. 100 is the exact figure and you can't go below or above the numbers and you have to use the entire $100. If there is no kind of tax applied how many of each of the following balls will you be able to buy:

Green Balls costing $6
Yellow Balls costing $3
Black Balls costing $0.10

Now, how many of each must you buy to fulfil the condition given?

What makes this number unique: 8,549,176,320?

What seven-letter word has hundreds of letters in it?

One is to three as three is to five and five is to four and four is the magic number.
What is the pattern?

When monkey rotate the gear, which mark will be hit 1 or 2 ?

Which word is least like the others? Third, fourth, fifth, sixth, seventh, eighth, ninth?

You are provided with a grid (as shown in the picture). Can you fill the squares with numbers 1-8 in a manner that none of the two consecutive numbers are placed next to each other in any direction (vertically, horizontally or diagonally?)

1. Where does Easter come from before Valentine's Day?

2. Do you know what is in the middle of Valentine's?

3. What did the lady bee say to the man bee on the occasion of Valentine's Day