A Rectangular Tank Has Width $3 \mathrm { ft }$ , Height

Multiple Choice

A rectangular tank has width $3 \mathrm { ft }$ , height $2 \mathrm { ft }$ , and length $7 \mathrm { ft }$ . It is filled with equal volumes of water and oil. The oil has a weight density of $50 \mathrm { lb } / \mathrm { ft } ^ { 3 }$ and floats on the water. Find the force exerted by the mixture on one end of the tank. (The weight density of water is $62.4 \mathrm { lb } / \mathrm { ft } ^ { 3 }$ .)

A) $319 \mathrm { lb }$
B) $356 \mathrm { lb }$
C) $337 \mathrm { lb }$
D) $169 \mathrm { lb }$