E 
Alex and Bob love to fold cranes. For a bag of $N$ cranes, Alex will need $2$ hours to complete while Bob will need $3$ hours. One morning, Alex and Bob started to fold cranes at the same time. After $30$ minutes, Alex rested for $10$ minutes before continuing to fold cranes while Bob did not rest at all. When they finished a bag of $N$ cranes together, Alex folded $24$ more cranes than Bob. Find the value of $N$. 

a. $$60$$ 
b. $$90$$ 
c. $$120$$ 
d. $$150$$ 
e. $$180$$ 
f. None of the above 