Metal ductwork

The new hospital would require​ 5,840 feet of sheet metal ductwork. The order was too large for a single​ fabricator, so they decided to split the order among four fabricators. Fabricator 1 received an order for​ 2,500 feet, Fabricator 2 obtained an order for​ 1,200 feet, and Fabricator 3 was awarded a contract for​ 1,150 feet. How many feet of ductwork would be required of Fabricator​ 4?

Correct answer:

f₄ =  990 ft

Step-by-step explanation:

$$\begin{gathered} t=5840\text{ft} \\ {f}_1=2500\text{ft} \\ {f}_2=1200\text{ft} \\ {f}_3=1150\text{ft} \\ {f}_4=t-f_1-f_2-f_3=5840-2500-1200-1150=990\text{ft} \end{gathered}$$

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