Question

What is the smallest number which is reversed when 2 is added to its double?

Answer 1

25

Explanation:

Let the number be 10x+y.

So we have 2(10x+y)+2 = 10y+x, or

20x + 2y + 2 = 10y+x, or

19x=8y-2 …(1)

Try different values of x which satisfy (1) giving an integer value of y. Moreover x should be less than y. The only value of x is 2 which gives us y = 5.

So y = 5 and x = 2.

And the answer is 25.

We can prove this by simply doing the question's equation:

50(since it's the double of 25) + 2 =

50+2= 52

Hope this helps