It Takes the Owner\operator of a Dog Kennel 2 Hr $2 \frac { 1 } { 5 } \mathrm { hr }$

Multiple Choice

It takes the owner\operator of a dog kennel 2 hr to clean all of the cages. It takes his assistant 1 hr more than that to clean the same cages. How long will it take if they work together?

A) $2 \frac { 1 } { 5 } \mathrm { hr }$
B) $1 \frac { 3 } { 5 } \mathrm { hr }$
C) $1 \frac { 1 } { 5 } \mathrm { hr }$
D) $3 \frac { 1 } { 5 } \mathrm { hr }$
E) $1 \frac { 1 } { 3 } \mathrm { hr }$