the sum of the digits of two-digit numbers is 9. also,nine times this numbers is twice the number obtained by reversing the order of the digits find the numbers.
Answers
Answer:
ANSWER
Let the ten's digit no. be x and one's digit no. be y.
So the no. will be = 10x+y.
Given : x+y=9-----(I)
9(10x+y)=2(10y+x) ⇒88x−11y=0 -----(II)
On solving I and II simultaneously you will get x=1 and y=8.
Therefore your desired no. is 18.
Step-by-step explanation:
Solution :-
Let the unit digit and tens digits of the number be x and y
Number = 10y + x
Number after reversing the digits = 10x + y
According to the question,
⇒ x + y = 9 ... (i)
⇒ 9(10y + x) = 2(10x + y)
⇒ 88y - 11x = 0
⇒ -x + 8y =0 ... (ii)
Adding equation (i) and (ii), we get
⇒ 9y = 9
⇒ y = 1 ... (iii)
Putting the value in equation (i), we get
⇒ x = 8
Hence, the number is 10y + x = 10 × 1 + 8 = 18.