15/100*x=39
x=39*100/15
x= 260 is the total number of people who were asked
Answer:
7l=2l+r
Step-by-Step explanation:
Answer:
A- control group
Since group A is tested under normal condition, it is the control group. Control group is separated from other groups so that the independent variable being tested cannot influence the result.
Answer:
2.5 miles
Step-by-step explanation:
The relation between time, speed, and distance is ...
distance = speed × time
We can define t to be Stanley's swimming time. Then t+0.5 was his running time, and 2(t+0.5) was his biking time. His total distance covered is ...
64 = 9(t +0.5) +16(2(t +0.5)) +2.5(t)
64 = 43.5t +20.5 . . . . . . . simplify
43.5 = 43.5t . . . . . . . . . subtract 20.5
t = 1 . . . . . . . . . . . . . . divide by the coefficient of t
Stanley swam for 1 hour, so the distance he covered while swimming was ...
(2.5 mi/h)(1 h) = 2.5 mi
Stanley covered 2.5 miles while swimming.
_____
<em>Additional comment</em>
Stanley ran for 1.5 hours, covering 9×1.5 = 13.5 miles. He biked for 3 hours, covering 16×3 = 48 miles. His total distance was 2.5 +13.5 +48 = 64 miles, as given.
Answer:
Let's define the high temperature as T.
We know that:
"four times T, was more than 2*T plus 66°C"
(i assume that the temperature is in °C)
We can write this inequality as:
4*T > 2*T + 66°C
Now we just need to solve this for T.
subtracting 2*T in both sides, we get:
4*T - 2*T > 2*T + 66°C - 2*T
2*T > 66°C
Now we can divide both sides by 2:
2*T/2 > 66°C/2
T > 33°C
So T was larger than 33°C
Notice that T = 33°C is not a solution of the inequality, then we should use the symbol ( for the set notation.
Then the range of possible temperatures is:
(33°C, ...)
Where we do not have an upper limit, so we could write this as:
(33°C, ∞°C)
(ignoring the fact that ∞°C is something impossible because it means infinite energy, but for the given problem it works)
