Question

Hello people, please if you can give me a Hint with this, l only get half of the marks, what i am doing wrong here? thanks

Answer 1

Errors: Both of your upper bounds are wrong

You subtracted the upper bound from the upper bound

Explanation:

605 kg to the nearest 5 kg

lower bound is 602.5 (because it rounds up to 605)

upper bound is 607.4 (because it rounds down to 605)

Note: 607.5 would round up to 610

78 kg rounded to the nearest 1 kg

lower bound is 77.5 (because it rounds up to 78)

upper bound is 78.4 (because it rounds down to 78)

Note: 78.5 would round up to 79

Upper Bound - Lower bound is the maximum weight remaining on the elevator

607.4 - 77.5 = 529.9

529.9 ≤ 530 so YES the elevator is safe.