Jesse needs 8 1/4 feet of chain. He already has two small pieces each measuring 2 1/8 and 3 3/4 feet respectively. We shall add both lengths of chain in his possession for a start.
Available lengths = 2 1/8 + 3 3/4
The LCM of the denominators is 8, and thus we can now write,
17/8 + 15/4
(17 + 30)/8
47/8
Expressed as a proper fraction this becomes,
5 7/8
This means, while Jesse needs 8 1/4 feet of chain, what he has is just 5 7/8 feet of chain. To know how much more he would need to purchase, you simply subtract 5 7/8 from 8 1/4 and that becomes;
Length required = 8 1/4 - 5 7/8
Length req = 33/4 - 47/8
Length req = (66 - 47)/8
Length req = 19/8
Expressed as a proper fraction, this becomes
Length required = 2 3/8 feet
The correct answer is option B!