Answer:
The speed of the first car is 60 mph
Step-by-step explanation:
speed = distance/time
Solve the above equation for distance to get
distance = speed * time
or simply
d = st
Now we use this formula for distance to write an equation for each car.
Let s = speed of second car
Then since the speed of the first car is 10 mph faster, the first car's speed is s + 10.
The time the two cars traveled is equal but unknown, so let the time = t.
First car: speed = s + 10; time = t; distance = 120 miles
d = st
120 = (s + 10)t
(s + 10)t = 120 Equation 1
Second car: speed = s; time = t; 100 miles
d = st
100 = st
st = 100 Equation 2
Equations 1 and 2 form a system of 2 equations in 2 unknowns.
(s + 10)t = 120
st = 100
Distribute t in the first equation.
st + 10t = 120
From the second equation we know st = 100, so substitute 100 for st.
100 + 10t = 120
10t = 120
t = 2
The time traveled was 2 hours.
Equation 2:
st = 100
Substitute t with 2.
s * 2 = 100
s = 50
The speed of the second car was 50 mph.
The speed of the first car is s + 10.
s + 10 = 50 + 10 = 60
Answer: The speed of the first car is 60 mph
Answer:
o I = 4 cm, w = 9 cm, h = 3 cm
Step-by-step explanation:
The volume is given by V = l*w*h
w = 6 cm, I = 4,cm, h = 4 cm V= 6*4*4 = 96
o w = 7 cm, h = 3 cm, I = 5 cm V = 7*3*5 =105
o I = 4 cm, w = 9 cm, h = 3 cm V = 4*9*3 =108
o h = 5 cm, w = 6 cm, I = 3 cm V = 5*6*3 =90
The largest volume is
o I = 4 cm, w = 9 cm, h = 3 cm V = 4*9*3 =108
For these problems, the this number is this percent of what number ones, turn the percent into a decimal.
Do this by moving the decimal two places to the left.
0.25 is the decimal.
Now divide the whole number by the decimal.
60/0.25=240
60 is 25% of 240
Answer:
∴35.97 mg caffeine would be left in the system after 5 hours.
Step-by-step explanation:
Given that,
A cup of coffee has approximately 310 mg of caffeine.
Caffeine decrease at a rate 35% per hour.
Exponential Function:
y(t)= Amount caffeine after t hours
= Initial amount of caffeine
r= rate of decrease
t = Time in hour.
Here y(t)=?, = 310 mg, r=35%=0.35, t= 5 hours
=35.97 mg
∴35.97 mg caffeine would be left in the system after 5 hours.
Answer:
Step-by-step explanation:
A store has a 20% sale on everything.
So since you are saving 20%, you will only be paying 80% of the original price.
To find the sale price use the following formula:
Sale price = 80% x original price
They told us the original price = 350 AED
This means:
Sale price = 80% x 350
I think it would be easiest to change 80% into a fraction if you don't have a calculator :)
80% = 
This means that the
Sale Price= 
x 350 = 280 AED
