Question

A track star in Arizona ran the 100 meter dash event is six track meets. Her average time for all six meets was 11.8 seconds. She could not find the record for her running time in the last meet, but she was all the other ones: 11.7 seconds, 11.6 seconds, 12 seconds, 12.1 seconds, 11.9 seconds. What was her running time for her last meet?

Answer 1

Answer:

A track star in Arizona running time in the last meet was 11.5 seconds.

Step-by-step explanation:

Given:

average time for all six meets = 11.8 seconds.

Time for 1st meet = 11.7 seconds.

Time for 2nd meet = 11.6 seconds.

Time for 3rd meet = 12 seconds.

Time for 4th meet = 12.1 seconds.

Time for 5th meet = 11.9 seconds.

We need to find the running time for her last meet.

Solution:

Let the running time for her last meet be 'x'.

So we can say that;

average time for all six meets is equal to sum of Time for 1st meet, Time for 2nd meet, Time for 3rd meet,Time for 4th meet, Time for 5th meet and time for her last meet and then divided by 6.

framing in equation form we get;

$\frac{11.7+11.6+12+12.1+11.9+x}{6}=11.8\\\\\frac{59.3+x}6 =11.8$

Now Multiplying both side by 6 we get;

$\frac{59.3+x}{6}\times 6= 11.8\times6\\\\59.3+x=70.8$

Now Subtracting both side by 59.3 we get;

$59.3+x-59.3=70.8-59.3\\\\x=11.5 \ s$

Hence A track star in Arizona running time in the last meet was 11.5 seconds.