Matematika

Pertanyaan

A plumber had two pipes. The ratioof the length of the longer pipe to the shorter pipe was 9 : 2 when he cut 1.65 meter from the longer pipe the remaining length was 3 times that of the shorter pipe. Find the length of the shorter pipe in metres

2 Jawaban

  • x = the longer pipe
    y = the shorter pipe
    x : y = 9 : 2
    2x = 9y
    x = 9y/2

    x - 1,65 = 3y
    x = 3y + 1,65

    x1 = x2
    9y/2 = 3y + 1,65
    9y = 2(3y + 1,65)
    9y = 6y + 3,3
    9y-6y = 3,3
    3y = 3,3
    y = 3,3/3 = 1,1 m

    So the shorter pipe is 1,1 meter
  • let
    x be the length of the longer pipe and
    y be the length of the shorter pipe

    the given ratio means
    [tex] \frac{x}{y} = \frac{9}{2} [/tex]
    so,
    [tex]x = \frac{9}{2} y[/tex]

    when he cut 1.65 meter from the longer pipe the remaining length was 3 times that of the shorter pipe, it means
    [tex]x - 1.65 = 3y \\ x = 3y + 1.65[/tex]

    substitute x
    [tex]x = x \\ \frac{9}{2} y = 3y + 1.65 [/tex]

    multiply by 2 we obtain
    [tex]9y = 6y + 3.3 \\ 9y - 6y = 3.3 \\ 3y = 3.3 \\ y = 1.1[/tex]
    hence, y = 1.1, so the length of the shorter pipe is 1.1 meter

Pertanyaan Lainnya