Answer:
36 mph
Step-by-step explanation:
The appropriate relations are ...
time = distance/speed
speed = distance/time
Suppose the race has a total length of 360 miles. Then half the race is 180 miles.
The cyclist's time on the first half is (180 mi)/(30 mi/h) = 6 h.
The cyclist's time on the second half is (180 mi)/(45 mi/h) = 4 h.
The total time is 10 h for the total distance of 360 mi, so the average speed is ...
(360 mi)/(10 h) = 36 mi/h
_____
The length of the race doesn't matter. The above numbers make the math convenient. The average is computed from ...
1/((1/2)/30 + (1/2)/45) = 2/(1/30 +1/45) = 2·30·45/(30+45) = 36
This is the <em>harmonic mean</em> of the numbers 30 and 45.
At the same rate, the price of 12 bottles of water at the convenience store would be
(12/10)·$11.80 = $14.16 . . . . . this is more than $13.80
On average the cost for the same number of bottles of water is higher at the convenience store. The grocery store has the better buy.
Step-by-step explanation:
1/2 b×h that's the area
The answer is 7 square units
Answer:
84
Step-by-step explanation:
Step-by-step explanation:
To find the percentage of dog movies , first of all find the total ratio, i. e 2+3 = 5
then , % of dog movies = ratio of dog movies/ total ratio x 100/1
= 2/5 x 100/1
= 40 %
