Let u be speed while Lisa drove 240 miles and t be the time in completing 240 miles.
We have been given that Lisa increased her speed 20 mph than initial speed over next 540 miles. So her speed on next 540 miles will be
mph.
Further more we are given that she took 3 hours more to complete the next 540 miles of the trip than she took in completing initial 240 miles. So she took
hours in completing next 540 miles.
Since we know 
Now we will substitute our given values in our equation and find out the unknowns. After substitution we will get two equations and two unknowns.

Now we will substitute equation 1 in equation 2

Upon solving this equation, we get

Therefore, total time for Lisa to complete the entire trip is 6+6+3 = 15 hours.
And we know that total distance covered is 240+540 = 780 miles
Hence, average speed

10 yards per 5min is
10yrd/5min
first convert it into yards per minute
10yrds/5min = 2yrds/1min
let's first so the yards to feet part first
1 yrd = 3 feet
2yrds/min * 3ft/1yrd
so now we have
6yrds/min
now convert minute to hour
1 hour = 60 mins
6yrds/min * 60min/1hr
=360/1hr
remember so that units cancel
Answer:
C (i think i did it correctly)
Step-by-step explanation:
9 times 12 is 108 -> 108 - 60 = 1 hour and 48 minutes -> 48 plus 4 = 7:52am
X^2-48 can be viewed as a difference of squares which would factor to:
(x+√48)(x-√48)
So b=√48