I am a two-digit number. If you reverse my digits and add 27, the result is the original number. What number am I?
Category: Math · Difficulty: hard
Hint: Think about how reversing digits affects their value.
Answer
72
Explanation
Let the number be 10a + b, where a is the digit in the tens place and b is in the units. Reversing gives 10b + a. The equation is: 10b + a + 27 = 10a + b. Solving yields a = 7 and b = 2.
This is a hard math riddle — a tricky one that takes a little thought. The answer is 72.
More Math riddles
- I am a two-digit number whose square is also a two-digit number. What number am I?
- Three consecutive integers, when summed together, give a number that is twice the middle integer. What is…
- A two-digit number is such that if you swap its digits, the new number is 27 less than the original. What is…
- Solve for x: 4(x - 3) + 2 = 2x + 10. What is the value of x?
- A train leaves the station traveling at 60 km/h. Another train leaves the same station 30 minutes later…
- You roll two six-sided dice. What is the probability that the sum of the two dice equals 7?
- In a strange alien world, they count in base 6. What is the base 10 equivalent of the base 6 number 245?
- In a certain sequence, each number is the sum of the previous two, starting from 1 and 2. What is the 10th…