Upper bound, lower bound

[thewantedguy]

Can anyone please Give me any notes regarding the upper bound, lower bound thingy..
n pls solve this question
Q : Each box has a mass of 1.5 kg to the nearest 0.1 kg
The Empty container has a mass of 6 kg to the nearest 0.5 kg
Calculate the greatest possible total mass of the container and 100 boxes..
Thanks in advance

 

[abcde]

AoA!
Let's deal with the boxes first! The degree of accuracy here is 0.1 kg.
=> Possible error = 0.1/2 = 0.05 kg.
=> Upper bound of the mass of each box = (1.5 + 0.05) kg = 1.55 kg.
Coming towards the container: the degree of accuracy here is 0.5 kg.
=> Possible error = 0.5/2 = 0.25 kg
=> Upper bound of mass of empty container = (6 + 0.25) kg = 6.25 kg.
Therefore, greatest possible total mass of the container and 100 boxes = 6.25 + 100(1.55) = (6.25 + 155) kg = 161.25 kg.
Is this the correct answer?

 

[thewantedguy]

Yeah its the correct answer Thanks bdw it means that everytime we have to divide the limit of accuracy by 2?

 

[abcde]

Yes, to find the possible error(P.E.).Then we add the P.E. to the mass/any reading to find the upper bound and subtract to find the lower bound, as the case may be.

 

[thewantedguy]

Thanks

 

[ibadsiddiqi]

abcde thanks. that was pretty helpful

 

[abcde]

You're welcome!

 

[thewantedguy]

If u could help me with these problems as well
viewtopic.php?f=25&t=8824