It takes George 1 hour longer to mow the lawn than it takes Henry. Working together, using two mowers, they can mow the lawn in 1 hour and 12 minutes. How long would it take Henry to mow the lawn by himself? [hint: Let x be the time taken by George. How much of the lawn does George mow in 1 hour? How much does Henry do in 1 hour? How much do they mow together in 1 hour?]

Respuesta :

Answer:

Step-by-step explanation:

Given

George take 1 hr longer than Henry

Let Henry take  x hr to complete the work

Therefore time taken by George is x+1 hr

Rate of George is [tex]\frac{1}{x+1} \hr[/tex]

Rate of Henry is [tex]\frac{1}{x} \hr[/tex]

They both complete the work in 1 hr and 12 min i.e [tex]\frac{6}{5} hr[/tex]

therefore they both mow in hr

[tex]\frac{1}{x+1}+\frac{1}{x}=\frac{5}{6}[/tex]

[tex]\frac{x+x+1}{(x+1)(x)}=\frac{5}{6}[/tex]

[tex]5x^2-7x-6=0[/tex]

[tex](x-2)(5x+3)=0[/tex]

[tex]x=2 hr[/tex]

thus George mow [tex]\frac{1}{3}[/tex] lawn in 1 hr

Henry mow [tex]\frac{1}{2}[/tex] lawn in 1 hr

both mow [tex]\frac{5}{6}[/tex] in 1 hr