I multiplied a natural number by 18 and another by 21 and

Home » Aptitude » Number System » Question

I multiplied a natural number by 18 and another by 21 and added the products. Which one of the following could be the sum?

Let the natural numbers be x and y.
∴ Required sum = 18x + 21y
= 3 (6x + 7y)
Hence, the sum is divisible by 3.
∴ Required answer = 2007