Every day Guy takes the same N sandwiches to work. Guy takes to work

Every day Guy takes the same N sandwiches to work. Guy takes to work how many more sandwiches that contain only ginger jam than sandwiches that contain only peanut butter ?

{Total} = {ginger} + {peanut } - {both ginger and peanut} + {neither}.

The question asks to find the value of {only ginger} - {only peanut}.

Notice that since there can be some some other kinds of sandwiches (say bacon), than {only ginger} might NOT equal to {ginger} - {both ginger and peanut} and the same way {only peanut} might NOT equal to {peanut} - {both ginger and peanut}. Thus {only ginger} - {only peanut} might NOT equal to ({ginger} - {both ginger and peanut}) - ({peanut} - {both ginger and peanut}) = {ginger} - {peanut}.

(1) Every day Guy takes to work 5 more sandwiches that do not contain peanut butter than sandwiches that do not contain ginger jam.

# of sandwiches that do not contain peanut butter is {Total} - {peanut}.
# of sandwiches that do not contain ginger jam is {Total} - {ginger}.

So, we are given that ({Total} - {peanut}) - ({Total} - {ginger}) = {ginger} - {peanut} = 5.

Not sufficient.

(2) Every sandwich Guy takes to work contains peanut butter or ginger jam or both --> {Total} = {ginger} + {peanut } - {both ginger and peanut}. So, the question becomes:

{only ginger} - {only peanut } = ({ginger} - {both ginger and peanut}) - ({peanut} - {both ginger and peanut}) = {ginger} - {peanut} = ?

Not sufficient.

(1)+(2) {ginger} - {peanut} = 5. Sufficient.

Answer: C.

Hope it's clear.