A girl is twice as old as her brother and half as old as her father. In 50 years, her brother will be half as old as his father. How old is the daughter now?

A tree doubled in height each year until it reached its maximum height over the course of ten years. How many years did it take for the tree to reach half its maximum height?

John replied, when asked how old he was. In 2 years he will be twice as old as he was five years ago.' How old is he ?

Can you find the missing number in the third row?
35 20 14
27 12 18
5 2 ?

Which three-digit number, made of consecutive digits, like 567, is 2 less than a cube and 2 more than a square?

A chicken farmer has figured out that a hen and a half can lay an egg and a half in a day and a half. How many hens does the farmer need to produce one dozen eggs in six days?

Find three whole, positive numbers that have the same answer when multiplied together as when added together.

Can you find a number that lies one third of the distance between 1/3 and 2/3?

Can you solve below mathematical equation?

2^1234 - 2^1233

In a competitive exam, each correct answer could win you 10 points and each wrong answer could lose you 5 points. You sat in the exam and answered all the 20 questions, which were given in the exam.
When you checked the result, you scored 125 marks on the test.

Can you calculate how many answers given by you were wrong?