20 men

20 men are supposed to complete a work in 10 days. After working for 5 days, they realize that only one-fourth of the work is done. How many more men they need to employ to complete the work on time?

Final Answer:

x =  10

Step-by-step explanation:

$$\begin{gathered} w=20\cdot 10=200 \\ {w}_1=5\cdot 20=100 \\ {w}_2=\frac{1}{4}\cdot w=\frac{1}{4}\cdot 200=\frac{1\cdot 200}{4}=\frac{200}{4}=50 \\ {w}_3=w-w_2=200-50=150 \\ {w}_3=(x+20)\cdot (10-5) \\ {w}_3/(10-5)=x+20 \\ x=w_3/(10-5)-20=150/(10-5)-20=10 \end{gathered}$$

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