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(a) One number is six times another number. The sum of their reciprocals is 2 1/3. Find the two numbers.

(b) 16 men took 9 days to build a 10-km railway track. How long would it take 20 men to build a 25-km railway track?

 Nov 4, 2023
 #1
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a)   Two numbers 

      x and 6x 

      1/x   + 1/6x = 7/3     <==== given ,        multiply entire  equation by x to get

      1 + 1/6 = 7/3 x 

        7/6 = 7/3 x 

          x = 7/6 * 3/7 = 1/2 

                  the other number is   3

 

 

b)    16 m * 9 d  / 10 km =   14.4 man days per km 

 

            25 km will require      25 * 14.4 = 360 man days         if you have 20 men then 18 days required 

 Nov 5, 2023

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