Mathematical Puzzles
Medium
1 min
A number is increased by 15 and then multiplied by 2. The result is 50. What was the original number?
Hint
Work backwards.
Answer
10.
Explanation
Let the number be x. Then 2(x + 15) = 50. Therefore x + 15 = 25 and x = 10.
Step-by-Step Solution
2(x + 15) = 50
x + 15 = 25
x = 10
x + 15 = 25
x = 10