Question

There are 3 bottles of alcohol in the pharmacy that need to be combined and relabeled. They are 1.5 L of 90%, 1 L of 70%, and 1.25L of 70%. What will the new label read?

Answer 1

Focus on bottle #1

You have 1.5 L of 90% alcohol. So how much pure alcohol is in the bottle?

Answer 2

90%
9090%

Answer 3

90%

Answer 4

90% of 1.5 L is what?

Answer 5

135

Answer 6

there's a decimal point missing

Answer 7

1.35

Answer 8

that's how many liters of pure alcohol you have in bottle #1

Answer 9

how about bottle #2?

Answer 10

.7 and .88

Answer 11

0.7 is correct for bottle #2, and 0.88 is close for bottle #3

Answer 12

don't round yet

Answer 13

.875

Answer 14

good

Answer 15

so how many liters of pure alcohol are there total?

Answer 16

3.75

Answer 17

that's the total of the mixtures (with water and other stuff in it)

Answer 18

what is the total of just the pure alcohol

Answer 19

3

Answer 20

again, don't round yet

Answer 21

add up those amounts you got previously

Answer 22

I don't know how many bottles

Answer 23

we found that

bottle #1 has 1.35 L of pure alcohol
bottle #2 has 0.7 L of pure alcohol
bottle #3 has 0.875 L of pure alcohol

Answer 24

what is the total of just the pure alcohol (in liters)

Answer 25

2.925

Answer 26

good

Answer 27

to sum things up, we have

2.925 L of pure alcohol

3.75 L of mixed solution (alcohol + water + other stuff)

Answer 28

divide the two (pure/mixed) and then multiply by 100 to get a percentage

Answer 29

ok

Answer 30

so now I need to know what % of alcohol I have in the 3.75 L bottles. The answer should be 78%alcolhol but not sure how to get that answer

Answer 31

the answer is 78%, correct

Answer 32

the way you find it is by following the steps shown above

step 1) find the amount of pure alcohol in each bottle
step 2) add up the amounts of pure alcohol
step 3) add up the amounts of the mixtures
step 4) divide the total amount of pure alcohol by the total amount of mixture
step 5) multiply that result by 100 to get a percentage

Answer 33

2.925/3.75=.78=78% so easy when you state step by step. thanks

Answer 34

you're welcome