The centre of the third figure is empty. What digit should fit inside?

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?

Find the missing number in the image below.

You are given a cube that is made with the help of 10x10x10 smaller cubes summing up to a total of 1000 smaller cubes. You are asked to take off one layer of the cubes.
How many remain now?

81 x 9 = 801. What must you do to make the this equation true?

In order to complete the racing competition, the Mexico racetrack has to submit its top and the most famous three horses to win the competition. Due to an electrical storm, all the records are cleared and no one knows which horse holds the record. They all look identical and it becomes even more difficult to differentiate the horses. There are 25 horses in the Mexico racetrack. But there can be only five horses at a time on the track. What will the least number of races that can be conducted to find out the three fastest horses?

How much will a 38° angle measure when looked at under a microscope that magnifies ten times?

Which point will the car reach to go out?

How can you make the following equation true by drawing only one straight line: 5+5+5=550 ?

How do you go from 98 to 720 using just one letter?