Answer:
40 mph.
Step-by-step explanation:
Suppose grandma's house is 30 miles away (any distance would do but 30 is convenient).
Speed = distance / time
time = distance / speed
Time to get there = 30/60 = 1/2 hour.
Time to get back = 30/30 = 1 hour
Average speed = total distance/ total time
= (30 + 30) / ( 1 + 1/2)
= 60 / 1.5
= 40 miles per hour.
You cannot take the average of the speeds directly
(60+ 30)/2 = 45 is not correct as you cannot average ratios ( speed is a ratio).
Answer:
14
Step-by-step explanation:
note that (f - g) = f(x) - g(x)
f(x) - g(x) = 3x² + 1 - (1 - x) = 3x² + 1 - 1 + x = 3x² + x
To evaluate (f - g)(2) substitute x = 2 into f(x) - g(x)
(f - g)(2) = 3(2)² + 2 = (3 × 4) + 2 = 12 + 2 = 14
Answer:
a = 337.214 m2
Step-by-step explanation:
hope this helps
Answer:
2.275%
Step-by-step explanation:
We start by calculating the z-score
Mathematically;
z-score = (x-mean)SD
here, x = 70.5
mean = 65.5
SD = 2.5
Substituting these values;
z = (70.5-65.5)/2.5
= 5/2.5 = 2
So we want to calculate the probability that;
P( z> 2)
We check the standard normal distribution table for this
That will be
0.02275
In percentage, this is 2.275 %
