Two-fifths of a number is 14 less than three-fourths of the same number. Find the number.

Let the number be $n$. Then $\frac{3n}{4}-\frac{2n}{5}=14$. Multiply every term by the LCM 20: $15n-8n=280$ → $7n=280$ → $n=40$. Check: two-fifths of 40 is 16, three-fourths is 30, and 30 − 16 = 14. The trap 2 comes from multiplying only the left side by 20 and leaving the 14 as it stands.