6400 workers were employed to construct a river bridge in four years.

1.	6400 workers were employed to construct a river bridge in four years. At the end of the first year, 25% workers were retrenched. At the end of the second year, 25% of those working at that time were retrenched. However, to complete the project in time, the number of workers was increased by 25% at the end of the third year. How many workers were working during the fourth year?
Answer» Given, Intial number of workers = 6400 At the end of first year = 25% retrenched At the end of second year = 25% retrenched At the end of third year = 25% increased So, Number of workers working during fourth year \(= 6400({1}-\frac{25}{100})({1}-\frac{25}{100})({1}+\frac{25}{100})\) \(= 6400\times\frac{3}{4}\times\frac{3}{4}\times\frac{5}{4}\) = 4500 workers

6400 workers were employed to construct a river bridge in four years. At the end of the first year, 25% workers were retrenched. At the end of the second year, 25% of those working at that time were retrenched. However, to complete the project in time, the number of workers was increased by 25% at the end of the third year. How many workers were working during the fourth year?

Answer»

Given,

Intial number of workers = 6400

At the end of first year = 25% retrenched

At the end of second year = 25% retrenched

At the end of third year = 25% increased

So,

Number of workers working during fourth year

\(= 6400({1}-\frac{25}{100})({1}-\frac{25}{100})({1}+\frac{25}{100})\)

\(= 6400\times\frac{3}{4}\times\frac{3}{4}\times\frac{5}{4}\) = 4500 workers