Christina has four daughters, and each of her daughters has a brother. How many children does Christina have?

O_er_t_o_

Complete the missing letters of the given word.

Take away my first letter, then take away my second letter. Then take away the rest of my letters, yet I remain the same. What am I?

Solve the counting riddle by identifying the number of triangles in the given picture.

I have no doors but I have keys, I have no rooms but I have space, you can enter but you can’t leave! What am I?

Using four sevens (7) and a one (1) create the number 100. Except for the five numerals, you can use the usual mathematical operations (+, -, x, :), root and brackets ()

Use only one mathematical symbol and all numbers (0-9) to get a sum of 99

Two in a corner, one in a room, zero in a house, but one in a shelter. What is it?

Can you decipher the below rebus?

PBLUESAISNUERSES

Solve the mathematical equation in the picture below.