Question

Toya can run one lap of the track in 1 min. 3 sec., which is 90% of her younger sister niki's time. what is niki's time for one lap?

Answer 1

Niki's time for one lap is 1 min 10 sec

Explanation:

Let

x ----> niki's time for one lap

Remember that

`1\ min=60\ sec`

so

`1\ min\ 3\ sec=60\ sec+ 3\ sec=63\ sec`

we know that

Niki's time for one lap multiplied by 0.90 (percentage in decimal form) must be equal to Toya's time for one lap

so

The linear equation that represent this problem is

`0.90x=63`

solve for x

`x=63/0.90=70\ sec`

Convert to min

`70\ sec=60\ sec+10\ sec=1\ min\ 10\ sec`