What is the next shape from answers A, B, C, and D figure?

A father's child, a mother's child, yet no one's son.

Who am I?

Can you count the number of triangles inside a triangle?

How many minutes are there in Feb 2017?

Note: The shortest answer is the correct answer.

Find out a multi-digit number that if multiplied by the number 9 or any of its multiplications products (i.e. 18, 27, 36, 45,..) will result in the multiplication factor repeated (n) number of times.

Three brothers Jacob, John, and James live in Mexico City. The product of the ages of these brothers is 175. Jacob and John are twins. How old is James?

As you can see that fifteen matches have been used to form an arrangement. What you have to do is remove any six of them to make them ten.

In the addition below, all digits have been replaced by letters. Equal letters represent equal digits and different letters represent different digits.
ABCABA
BBDCAA
ABEABB
ABDBAA
------- +
AAFGBDH
What does the complete addition look like in digits?

What four weights can be used to balance from 1 to 30 pounds?

Christina, Allison and Lena are 3 daughters of John a well-known Mathematician, When I asked John the age of their daughters. He replied "The current age of her daughters is prime. Also, the difference between their ages is also prime."

How old are the daughters?