Respuesta :
Answer:
Dad made 90 steps during that period.
Step-by-step explanation:
Let x,y,z be the steps made by dad,Anna and Todd.
Given that while dad made 3 steps, Anna made 5 steps.
That is [tex]\frac{x}{y}= \frac{3}{5}[/tex]
      [tex]y=\frac{5x}{3}[/tex]
And for every 3 steps Anna made, Todd made 5 steps.
That is [tex]\frac{y}{z}= \frac{3}{5}[/tex]
      [tex]z=\frac{5y}{3} =\frac{5(\frac{5x}{3}) }{3} =\frac{25x}{9}[/tex]
It is also given that total number of steps made by Anna and Todd is 400.
That is y+z=400
let us plugin y and z in terms of x.
    [tex]\frac{5x}{3} +\frac{25x}{9} =400[/tex]
    [tex]\frac{15x}{9} +\frac{25x}{9}=400[/tex]
    [tex]\frac{40x}{9}=400[/tex]
    [tex]x=400X\frac{9}{40} =90steps[/tex]
Hence Dad made 90 steps during that period.
