Five runners are entered into a competition. Four of the runners have had their turns. Their completing times are 7.4 s, 7.75 s, 7.09 s, and 7.86 s. What time must the last runner get in order to win
the competition?

Just writing anything above these numbers

Step-by-step explanation:

let t be winning time     t < 7.09 seconds

Step-by-step explanation:

let's first order the times from least to greatest:

7.09, 7.40, 7.75, and 7.86

Now, in order to have the winning time, the last runner must have a time less than the fastest runner so far. So, the winning time is less than 7.09 seconds.

Make sure to add units. I know that my teachers are REALLY picky about that, though yours may not care.

solution:

the given function is ,

      =

the three roots of this quadratic function is , 0 ,8 and 10.all the roots are real and rational.

if a quadratic equation is of the form ,

sum of the roots = a + b +c= 0+8+10=18=  

product of roots taken two at a time = a b + b c+ c a = 0+80+0=80 =  

product of roots = a b c = 0=  

there are 11 doors in a hall starting from 0 to 11.the entry in the hall is permitted through gate number 0 and exit is allowed through only gate number 8 and 10.so, three roots(0,8,10) of quadratic function is given by entry and exit route of this hall.