SOLUTION: Susan is 3 inches taller than her mom. Susan's sister is 2 1/3 feet shorter than her and 8/13 the height of her mother. How tall is Susan's mom?

Algebra ->  Expressions -> SOLUTION: Susan is 3 inches taller than her mom. Susan's sister is 2 1/3 feet shorter than her and 8/13 the height of her mother. How tall is Susan's mom?      Log On


   



Question 1121728: Susan is 3 inches taller than her mom. Susan's sister is 2 1/3 feet
shorter than her and 8/13 the height of her mother. How tall is
Susan's mom?

Found 3 solutions by josgarithmetic, MathTherapy, ikleyn:
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
Who is "her"? Susan?
PERSON         HEIGHT(in feet)
Susan          x%2B3%2F12
Mom             x
Sister         %28x%2B3%2F12%29-2%261%2F3=x%288%2F13%29

The variable is was assigned to Mother. Solve for x and evaluate x+3.

Answer by MathTherapy(10552) About Me  (Show Source):
You can put this solution on YOUR website!
Susan is 3 inches taller than her mom. Susan's sister is 2 1/3 feet
shorter than her and 8/13 the height of her mother. How tall is
Susan's mom?
Mom's height: highlight_green%28matrix%281%2C4%2C+5%2C+feet%2C+5%2C+inches%29%29
You'll NEVER get this answer if you try to solve the equation the other person gave you to solve. NEVER, in a million years!
That equation is: cross%28%28x%2B3%29-2%261%2F3=x%288%2F13%29%29

Answer by ikleyn(52781) About Me  (Show Source):
You can put this solution on YOUR website!
.

To solve the problem, you must have all dimensions in uniform / consistent units.

In this case, inches are preferred units.

Also, you need to know that 1 foot = 12 inches.


    Let x be the mother height, in inches.

    Then Susan's height is (x+3) inches.


    Susan' sister is 21%2F3 feet shorter than Susan.


    21%2F3 feet = 24+%2B+12%2F3 inches = 24 + 4 inches = 28 inches.


    Hence, as the condition states, the Susan's sister is 28 inches shorter than Susan.


    In other words, Susan's sister height is ((x+3) - 28) = (x-25) inches.


    The equation, from the condition, is


        x - 25 = (8/13)*x.


    ============>  13x - 13*25 = 8x  ====>  13x - 8x = 13*25  ====>  5x = 13*25  ====>  x = 13*5 = 65 inches = 5 ft and 5 inches.


    Answer.  The mother's height is 5 ft and 5 inches.

Solved.