What Adam and Eve do not have but the rest of the people have?

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

A man dies of old age on his 25 birthday. How is this possible?

A boy collects white seashells from the sea and brings them home every night. When he has enough of them, he decides to sell them to a trader.

The trader is ready to buy the shells and he asks the boy about the quantity. At this, the boy starts calculating. He has a giant box that contains 3 mini boxes. Two of them have another mini box inside. If the giant box can hold 50 shells, how many brown shells can he sell to the trader?

Before Mount Everest was discovered, what was the highest mountain in the world?

A man dies of old age on his 25 birthday. How is this possible?

Solve the following series:
AZ, GT, MN, __, YB

A gardener planted the Lemon trees in a mathematical ordered way (i.e. he planted a tree in rows).
He created a total of 19 rows of trees.

Note: There should be more than 2 trees to count as a row.

What is the minimum number of trees required by the gardener to have 19 rows of trees?

Which tank will fill first?

Why is a river so rich ?