An experienced bricklayer can work twice as fast as an apprentice bricklayer. After the bricklayers work together on a job for 8 h, the experienced bricklayer q

Question

An experienced bricklayer can work twice as fast as an apprentice bricklayer. After the bricklayers work together on a job for 8 h, the experienced bricklayer quits. The apprentice requires 10 more hours to finish the job. How long would it take the experienced bricklayer, working alone, to do the job?

Answer 1

Hi Hannah,

 

During the first 8 hrs the two worked together

and the apprentice was half as fast as the experienced bricklayer

 

let x = the time it would take the experienced bricklayer to finish the 8 hour work load

 

therefore x + .5x = 8

 

1.5x = 8

x = 12     (so it would take the experienced bricklayer 12 hrs to do the first part alone)

 

The second part took the apprentice 10 hours  but that is 2 times what it would take the experienced bricklayer

 

so 2x = 10

 

x = 5

 

now combine the two parts of the job (12 + 5) = 17

 

It would take the experienced bricklayer 17 hours to do the job alone

 

Hope this helps.