Final answer:
Mr. Johnson is not speeding as his speed of 56 miles per hour is less than the speed limit of 60 miles per hour.
Step-by-step explanation:
Mr. Johnson is driving at a speed of 90 kilometers per hour. To determine if he is speeding, we need to compare his speed to the speed limit of 60 miles per hour. First, we need to convert Mr. Johnson's speed from kilometers per hour to miles per hour. We know that 1 kilometer is equal to 0.62 miles. Therefore, 90 kilometers per hour is equal to 56 miles per hour. Since Mr. Johnson's speed of 56 miles per hour is less than the speed limit of 60 miles per hour, he is not speeding (b) No.