Ones digit: 1
Tens digit: 7
Hundreds digit: 5, 6
Only 1 can be used in the unit place (right)
Only 7 can be used in the tens place (middle)
5 or 6 can be used in the hundreds place (left)
571, 671
Rounding to nearest hundred: higher if equal or greater than 50, lower if below 50
Nearest hundred for 571: 600
Nearest hundred for 671: 700
Answer is 571