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 their time by 1/10. If their final time is 3.96 minutes what was their beginning time?

Answer 1

Answer:

The beginning time of relay race is 6.73 minutes

Step-by-step explanation:

Given as :

The final time of relay race = 3.96 minutes

Let The initial time of relay race = x minutes

At first, The time reduce by 2.1 min

So, The first time become = ( x - 2.1 ) min

At second , The time reduce by $\dfrac{1}{10}$ = 0.1

So, The time become =  ( x - 2.1 ) min - $\dfrac{x}{10}$ min

$\dfrac{10 (x - 2.1) - x}{10}$

Or,  $\dfrac{9 x - 21}{10}$

∵ final time of race = 3.96 min

∴ $\dfrac{9 x - 21}{10}$ = 3.96

Or, 9 x - 21 = 3.96 × 10

Or, 9 x = 39.6 + 21

Or, 9 x = 60.6

∴  x = $\dfrac{60.6}{9}$

i.e  x = 6.73 minutes

So, The beginning time = x = 6.73 min

Hence,The beginning time of relay race is 6.73 minutes Answer