Answer:
The number is 39
Step-by-step explanation:
Let the number at the tens place be x and the number at ones place be y.
Hence, The number is 10x + y.
From the question, the digit at ones place (y) is three times the digit at tens place (x). That is, y is three times x. This means
y = 3x ...... (1)
Also, When 54 is added to the number, its digits are reversed (That is, the resulting number would be 10y + x). This means
10x + y + 54 = 10y + x ...... (2)
Put the value of y = 3x from equation (1) into equation (2) to solve for x
Then,
10x + y + 54 = 10y + x
10x + 3x + 54 = 10(3x) + x
13x + 54 = 30x + x
13x + 54 = 31x
31x - 13x = 54
18x = 54
x = 54/18
x = 3.
Now, Put the value of x = 3 into equation (1) to solve for y
y = 3x
y = 3(3)
y = 9.
Hence, x = 3 and y = 9.
Since the number is 10x + y
Substitute the values of x and y.
Then,
10x + y = 10(3) + 9
=30 + 9
= 39
Hence, the number is 39.
