Question

Tanya and her brother are racing with their new bikes in the neighborhood. Their block is one mile long. Tanya's average speed is 0.15 mi/s and her brother's is 0.11 mi/s. Who will reach the end of block first, and how much time ahead of the other will they be?

Answer 1

Tanya

`2.43\ \text{s}`

Step-by-step explanation:

`d` = Distance traveled = 1 mile

`s_t` = Tanya's average speed =
`0.15\ \text{mi/s}`

`s_b` = Tanya's brother's average speed =
`0.11\ \text{mi/s}`

Time taken by Tanya

`t=(d)/(s_t)\\\Rightarrow t=(1)/(0.15)\\\Rightarrow t=6.67\ \text{s}`

Time taken by Tanya's brother

`t=(d)/(s_b)\\\Rightarrow t=(1)/(0.11)\\\Rightarrow t=9.1\ \text{s}`

So Tanya will reach the end of the block first.

She will reach the end of the block by
`9.1-6.67=2.43\ \text{s}`