A Ricardo can paint a set of kitchen cabinet in 6 hours. His father can do it in 4 hours. How long
will a take them if they work together?


PLSSS HELPP MEE

Respuesta :

The time it will a take them for both ricardo and his father to finish the painting if they work together is;

t = 2.4 hours

Time for ricardo to paint the set of kitchen cabinets = 6 hours

Time for Ricardo's father to finish painting = 4 hours

This means that ricardo in 1 hour paints 1/6 of the cabinets

His father in 1 hour paints 1/4 of the cabinets

If they work together, in one hour, they would have painted;

1/6 + 1/4 = 5/12 of the cabinet

  • If 5/12 of the cabinet is done in an hour,

then 12/12 will be done in; ((12/12) × 1)/(5/12)

⇒ 1 × 12/5

⇒ 2.4 hours

Read more at; https://brainly.com/question/8317268

The correct answer is:  " 2 hours and 24 minutes ";

or; write as:  " 2.4 hours " .

____

Step-by-step explanation:

[tex]\frac{x}{4} + \frac{x}{6} = 1[/tex]  ;  → { " 1 (one) whole job." }.

       We want to solve for "x" ; the total time, in "hours", that will take them if they work together.
        What is the LCD (least common denominator of "4" and "6" ?
→  Note that "4 * 6 = 24" ;  so, "24" would work, but let's see if we can find the LCD —a number less then "24" ;

4:  2, 4,  12, 16, 20, 24,

6: 1, 2, 3, 6, 12

⇒  We see that "12" is the LCD.
_____
So, " [tex]\frac{x}{4} = \frac{?}{12}[/tex] " ;  to solve for "?" ;

 →  4 * (what value?) = 12 ?
   →   12 ÷ 4 = (that value) ; ⇒   =  " 3 " .
 _____
So:  [tex]\frac{x}{4} = \frac{(x*3)}{(4*3)} = \frac{3x}{12}[/tex] ;
_____
 Now:  " [tex]\frac{x}{6} = \frac{?}{12}[/tex] " ; to solve for "?" ;

→  6 * (what value?) = 12 ?
   →   12 ÷ 6 = (that value) ;  ⇒   =  " 2 " .

 _____

So:  " [tex]\frac{x}{6} = \frac{(x*2)}{(6*2)} = \frac{2x}{12}[/tex] ;

Now:  →  [tex]\frac{x}{4} + \frac{x}{6} = 1[/tex] ;

Substitute our converted values:
         →   [tex]\frac{3x}{12} + \frac{2x}{12}=1[/tex] ;

Then simplify the "left-hand side" of the equation:
_____
        →   [tex]\frac{3x}{12} + \frac{2x}{12} = \frac{(3x+2x)}{12}[/tex]  = [tex]\frac{5x}{12}[/tex]  ;

Now, rewrite the simplified equation; and bring down the "1" :
_____

        →   [tex]\frac{5x}{12} = 1[/tex]   ;

Now, solve for "x" ; as follows:
_____
 ⇒   5x  =  ( 1 * 12 )  ;

  →   5x  =  12  ;

Now, divide Each Side of the equation by "5" ;

to isolate "x" on one side of the equation; & to solve for "x" (in hours):
 _____
  →   5x / 5  =  12 / 5  ;

_____
to get:   x =  (12/5) hours.
_____
Now:  We have (12/5) of 1 hour ;     24/10

Note the exact conversion:  " 60 min. = 1 hr." :

So, 12/5 of 60 minutes;

=  " [tex]\frac{12}{5}[/tex] * [tex]}\frac{60}{1}[/tex] "  (minutes) ;
____
The "5" cancels to a "1" ;  and the "60" cancels to a "12" :

  {since:  "60 ÷ 5 = 12" ;  & since:  "5 ÷ 5 = 1 " .}.

→ And we can rewrite as:
    " [tex]\frac{12}{1} * \frac{12}{1}[/tex] "  (minutes) =  "12 * 12" minutes =  144 minutes.
⇒  " 144 minutes" equals:  How many hours?  " 144 ÷ 60  =  2.4  hours " ;

or; more specifically:

⇒ We have "2 hours and _(some) minutes".

→ that is;  " 2 hours plus 0.4 hour(s) " .

 [tex]\frac{(0.4) hr}{1}*\frac{(60)min}{1 hr} = [(0.4)*(60)] minutes[/tex] ;

                              =  24 minutes.

____

Alternate method:
____
(12/5 hours) = (12 ÷ 5) hours =  
" 2.4 hours " ;  (and continue if desired).
____

So:  The correct answer is:  " 2 hours and 24 minutes ";

                                       or; write as:  " 2.4 hours " .

____
Hope this is helpful to you!  Best of luck!

____