The first machine can produce 2,100 shirts in 140 min, then the shirts per minute it can produce is:
[tex]\frac{2100\text{ shirts}}{140\text{ min}}=15\text{ shirts per minute}[/tex]The second machine can produce 2,400 shirts in 120 min, then it can produce in one minute:
[tex]\frac{2400\text{ shirts}}{120\text{ min}}=20\text{ shirts per minute}[/tex]If the two machines work together, they can produce 15+20=35 shirts per minute, then to produce 7,350 shirts it will take:
[tex]\begin{gathered} \frac{35\text{ shirts}}{1\min }=\frac{7350\text{ shirts}}{x} \\ x=\frac{7350\text{ shirts}\cdot1\min }{35\text{ shirts}} \\ x=210\text{ min} \end{gathered}[/tex]The answer is 210 minutes.
