Answer:
Original number = 31
Step-by-step explanation:
Given : The ones digit of a number is 3 times the tens digit. If the digits are reversed, the new number is 18 more than the original number.
To find : The original number.
Solution : Let x = 10's digit and y= unit digit
Then the original number = 10x+y
Situation 1 - 'The ones digit of a number is 3 times the tens digit'.
Situation 2- 'If the digits are reversed, the new number is 18 more than the original number'.
Now, we solve the situation 2,
Put value of y from situation 1, y=3x
Put back in situation 1,
Therefore, x=1 and y=3 so, the number is 30+1=31
Original number = 31