Question

Which number in the set {6, 12, 18, 36} satisfies the equation 6x - 18 = 54?

Answer 1

Here we can go for trial and error,

Taking x=6

So equation will be 6*6-18 which gives 18

and is not equal to 54

So it's, not 6

Trying 12

6*12-18

Which is 54 and so correct answer is x=12