Question

The track team is trying to reduce their time for a relay race. First they reduce their time by 2.1 minutes. Then they are able to reduce that time by 10 If their final time is 3.96 minutes, what was their beginning time? Show or explain your reasoning.

Answer 1

Answer: 15.7 minutes

Step-by-step explanation:

Let x be the time in the beginning (in minutes).

Given: The track team is trying to reduce their time for a relay race.

First they reduce their time by $t_1=$2.1 minutes.

Then they are able to reduce that time by $t_2=$10

If their final time is 3.96 minutes, then

$x-t_1-t_2=3.6\\\Rightarrow\ x=3.6+t_1+t_2\\\Rightarrow\ x=3.6+2.1+10\\\Rightarrow\ x= 15.7$

Hence, their beginning time was 15.7 minutes.