The number obtained by interchanging the two digits of a two-digit number is less than the original number by 45. If the sum of the two digits of the number so obtained is 13, then what is the original number?
Correct answer: B. 94
- A. 49
- B. 94
- C. 83
- D. Either (a) or (b)
- E. None of these
Explanation
Let the original number be 10a + b and its reversal 10b + a. Since the reversal is 45 less, 9(a - b) = 45, so a - b = 5; with a + b = 13, the digits are a = 9 and b = 4, giving 94. A likely choice is option a, 49, from selecting the reversed number instead of the original number.
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? [email protected]
About Linear Equations
Linear equations contain variables only to the first power and produce straight-line relationships when represented graphically. Problems involve solving equations with brackets, fractions, and variables on both sides, forming equations from statements, and handling simultaneous linear equations, which differ from quadratic equations by having no squared variable.
Practise Algebra
269 free Algebra MCQs from Mathematics, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Mathematics questions like this
Mathematics is on 76 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
More Linear Equations questions
In a three digit number, the hundred digit is 2 more than the tens digit and the units digit is 2 less than the tens digit. If the sum of the digits is 18, find the number?
When 2 is added to half of one-third of one-fifth of a number, the result is one-fifteenth of the number. Find the number?
Masood's age 18 years hence will be thrice his age four years ago. Find Masood's present age?
The sum of the digits of a two-digit number is 12. The difference of the digits is 6. Find the number?
The tens digit of a two-digit number is two more than its unit digit. The two-digit number is 7 times the sum of the digits. Find the units digits?
Solve the equation for x : 6x - 27 + 3x = 4 + 9 - x