Some math puzzles look simple but hide a clever twist that leaves people debating the answer. Consider this equation: 230 − 220 ÷ 2 = ? One person says the answer is 120, while a Math PhD gives the surprising response 5! So, which answer is correct? The secret lies in understanding both the order of operations and a special mathematical symbol.
Using the standard PEMDAS/BODMAS rule, division must be completed before subtraction. First, calculate 220 ÷ 2 = 110. Then subtract the result from 230: 230 − 110 = 120. Therefore, the numerical answer to the original equation is indeed 120. The first person has solved the calculation correctly.
But what about the Math PhD’s answer? In mathematics, an exclamation mark placed after a number can represent a factorial, not excitement or punctuation. The expression 5! means multiplying 5 by every positive whole number below it down to 1: 5 × 4 × 3 × 2 × 1 = 120. So even though the PhD wrote a different-looking answer, its numerical value is exactly the same.
The surprising verdict: both answers are correct! 🧠 The equation evaluates to 120, while 5! also equals 120. The trick isn’t complicated arithmetic—it’s recognizing that two different mathematical expressions can represent the same number. This puzzle is a fun reminder to pay attention to symbols and notation before deciding someone has made a mistake. Did you spot the factorial trick right away, or did the PhD’s answer leave you confused?
