Aboat goes 3/4 hours with a speed of 8 mph and 1/3 hours with a speed of 12 mph. what distance did the boat cover in all this time?

10 miles

Step-by-step explanation:

Given: Boat goes hours with 8 mph       (i)

           Boat goes hours with 12 mph       (ii)

Now, lets find out distance separately to get total distance.

Formula for finding distance is

D=

D=   (i)

D=

∴ D1= 6 miles (i)

D= (ii)

∴D2= 4 miles  (ii)

To find total distance, we will add d1 and d2

Total distance =

∴ Total distance =

= 10 miles is the total distance covered by boat in all this time.

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.