Answer:
1. 474
2. 397
Step-by-step explanation:
1. If the three-digit number is xyz, then y = z + 3.
When rounded to the nearest ten and reduced by 320, the result is 150. 150 + 320 = 470, so x = 4. y = 6 if z ≥ 5, and y = 7 if z < 5.
So the number is either 463 or 474. 463 doesn't round to 470, so the answer is 474.
2. If the three-digit number is xyz, then z = x + 4. y is the largest of the three digits; since all the digits are odd, y is either 5, 7, or 9. So z is either 5 or 7, and x is either 1 or 3.
When rounded to the nearest hundred and reduced by 100, the result is 300. 100 + 300 = 400, and y > 5, so xyz is rounded up to 400, which means x = 3. So z = 7 and y = 9.
The answer is 397.
The answer is a total of 9 hours
