Q.2 A positive number is 5 times another number. If 21 is added to both the numbers, then one of the new numbers becomes twice the other new number. What are the numbers?
Let the No.1 = x
Then the second no. No.2 = 5x.
Now the question states that if we add 21 to both numbers one number becomes twice of the other.
i.e., 2(x + 21) = 5x + 21
or 2x + 42 = 5x + 21
Transposing 2x to the RHS and 21 to the LHS:
21 = 5x - 2x = 3x
or x = 7
Thus the two numbers are 7 and 35 . (Since No.2 = 5x)