janet weighs 20 pounds more than Anna. If the sum of the weights is 250 pounds, how mush does each girl weigh?

Question

i dont understand this question please help me solve it today.

Answer 1

You have asked the right question!  Indeed, the key to solving word (story) problems is to understand them.  And the key to understanding them is to be able to translate the words into concise, precise math expressions.  Let's do that:

 

First, assign variable names (letters) to each important value:    Let J be Janet's weight.  Let A be Anna's weight.

 

Now translate:

   "Janet weighs 20 pounds more than Anna"      means J = 20 + A         (PLZ compare words to formula)

   "the sum of the weights is 250 pounds"        means J + A = 250         (follow how this is done?)

   "how much does each girl weigh?"       means         report J, A

 

Now, the math is easy!

           J  = 20 + A        [equation 1]

 

           J + A  = 250            [eq2]

           J -  A  = 20              [use eq1 and subtract A from both sides]

          ----------------               [we will use elimination method]

          2J  + 0  = 270           [add these two equations]

              J = 135                [divide both sides by 2]

 

Put this value for J into eq1.

          135  = 20 + A

          115 = A                  [subtract 20 from both sides]

 

Now, check (very important):

    Does Janet weight 20 pounds more than Anna?  Or, is 135 = 20 + 115  ?     yes

    Is  135 + 115 = 250  ?     yes

 

Answer 2

Janet is 20 lbs more than Anna i.e. A+20=J or  A-J= -20
Anna and Janet combined weight is 250 i.e. A+J=250

 

Add both equations gives : 2A=230 i.e A=115

 

J=250-115=135

 

Anna=115lbs, Janet=135lbs