Can you count the number of triangles in the picture below?

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

Solve the mathematical equation in the picture below.

Find the next number in the series

12, 20, 40, 72, 116, 172 ?

When it's bad luck to meet a black cat?

A mathematician couple was having a Frappuccino in Starbucks sitting opposite to each other. Suddenly the guy noticed the text written on the paper in front of them and exclaimed that it was wrong. The girl denied it and said it is appropriate. Both are correct. What is written on the paper?

A certain street contains 100 buildings. They are numbered from 1 to 100. How many 9's are used in these numbers?

I look flat, but I am deep. Hidden realms I shelter. Lives I take, but the food I offer. At times I am beautiful. I can be calm, angry, and turbulent. I have no heart but offer pleasure as well as death. No man can own me, yet I encompass what all men must have. What am I?

When a clock is observed, the hour hand is at a minute mark and the minutes hand is six minutes ahead of it.

When the clock is observed again after some time, the hour hand is precisely on a different minute mark and the minute hand is seven minutes ahead of it.

Can you calculate how much time has elapsed between the two observations?

What does the below rebus riddle means?