Four times a number is 21 more than the number. What is the number?

I think the answer is 7!

Four times a number is 21 more than the number ----> 4x = 21 + x
3x = 21
x = 7

Anna "thought" the answer is 7
Now you can be 100% sure that the answer is 7

Very funny.....

Princess Anna -- at least Prof Reiny showed the student how he got the right answer.

Yeah, guess your right. I wasn't really sure about this one.....

but, yeah the answer is
7 as Reiny has just explained.

To find the number, let's define a variable and set up an equation based on the given information. Let's call the number "x".

According to the question, four times a number is 21 more than the number. Mathematically, we can write this as:

4x = x + 21

Now, we can solve this equation to find the value of x.

To do that, we'll first simplify the equation by combining like terms:

4x - x = 21

This becomes:

3x = 21

Next, we isolate x by dividing both sides of the equation by 3:

3x/3 = 21/3

Simplifying further:

x = 7

Therefore, the number is 7.