Answer: it will take them 48 minutes.
Step-by-step explanation:
John can mow a lawn in 80 minutes. This means that the rate at which he moans the lawn per minute is 1/80
Rocky can mow the same lawn in 120 minutes. This means that the rate at which Rocky can mow the same lawn per minute is 1/120
If they work together, they would work simultaneously and their individual rates are additive. This means that their combined working rate would be
1/80 + 1/120 = 200/9600 = 1/48
Assuming it takes t hours for both of them to clean the room working together, the working rate per hour would be 1/t. Therefore,
1/48 = 1/t
t = 48 minutes
To find the volume of something (freezer in this case) use the formula
Length x width x height
72.5 x 24.5 x 36 = <span>63945
63945 is your answer (if it is inch</span>²)
if not, you will have to use proportions to change it to the correct one
hope this helps
Answer:
Question 1 (1 point)
1. An object has a mass of 25g and a volume of 5ml
a
10
b
8
c
5
d
7
Question 2 (1 point)
2. An object has a mass of 30g and a volume of15ml. What is the density?
a
10
b
2
c
3
d
5
Question 3 (1 point)
3. An object has a mass of 200g and a volume of 100ml. What is the density?
a
2
b
4
c
6
d
8
Question 4 (1 point)
4. An object has a mass of 17g and a volume of 2ml. What is the density?
a
2.4
b
2
c
8
d
8.5
Question 5 (1 point)
5. An object has a mass of 20g and a volume of 5ml. What is the density?
a
2
b
4
c
10
d
2.5
Question 6 (1 point)
6. An object has a mass of 75g and a volume of 75ml. What is the density?
a
6
b
1
c
7
d
8
Question 7 (1 point)
7. An object has a volume of 100ml and a mass of 2oo ml. What is the density?
a
0.5
b
1
c
4
d
2.5
Question 8 (1 point)
8. An object has a volume of 5ml and a mass of 650 g. What is the density?
a
110
b
120
c
130
d
200
Question 9 (1 point)
9. An object has a mass of 15g and a volume of 5ml. What is the density?
a
2.5
b
7
c
3
d
2.56
Question 10 (1 point)
10. An object has a mass of 13g and a volume of 2ml. What is the density?
a
6.5
b
3.7
c
4
d
Step-by-step explanation:
<span>Standard deviation for mean of n objects = (square root n) x s.d. for one
object.
So you need (2.8/0.5)^2 or around 32.</span>
