8th Class
Mathematics
Algebraic Expressions
Question Bank
Algebra
question_answer
In a two digit number, ten's digit is twice the unit's digit. The number formed by interchanging the digits is 36 less than the original number. Find the number.
A)48
B)70
C)72
D)84
Correct Answer:
D
Solution :
10
1
\[2x\]
\[x\]
The number is 21x If the digits are interchanged
10
1
\[x\]
\[2x\]
the number = 12x \[{{2}^{2x-y}}=32\] \[\Rightarrow \] \[{{2}^{2x-y}}={{2}^{5}}\] \[\Rightarrow \] The number\[2x-y=5\]