10th Class Mathematics Pair of Linear Equations in Two Variables Question Bank MCQs - Pair of Linear Equations in Two Variables

The 2 digit number which becomes \[(5/6)th\] of itself when its digits are reversed. The difference in the digits of the number being 1, then the two digits number is:

A) \[45\]

B) \[54\]

C) \[36\]

D) None of these

Correct Answer: B

Solution :

[b] If the two digits are x and y, then the number is \[10x+y\].

Now, \[\frac{5}{6}(10x+y)=10y+x\]

Solving, we get \[44x+55y\]

\[\frac{x}{y}=\frac{5}{4}\]

Also \[x-y=1\] Solving them. we get \[x=5\] and \[y=4\].

Therefore, number is 54.