1. The problem is to simplify the expression $5\sqrt{16}$.\n\n2. Recall that $\sqrt{16}$ means the square root of 16, which is the number that when squared gives 16.\n\n3. Since $4^2 = 16$, we have $\sqrt{16} = 4$.\n\n4. Now multiply by 5: $5 \times 4 = 20$.\n\n5. Therefore, $5\sqrt{16} = 20$.