The quantity of water (in ml) needed to reduce 9 ml shaving lotion containing 50% alcohol to a lotion containing 30% alcohol is:
a. 4
b. 5
c. 6
d. 7
e. 8
Answer : c
this is how i solved it, but it was wrong -
In 9 ml lotion, 4.5 ml - alcohol and 4.5 - water.
Let X be the amount to water added to bring down the alcohol level to 30%. Then,
[(X + 4.5)/ (9 + X) ] * 100 = 30
This way, i get a negative value for X. Where am i going wrong? Someone please help
a. 4
b. 5
c. 6
d. 7
e. 8
Answer : c
this is how i solved it, but it was wrong -
In 9 ml lotion, 4.5 ml - alcohol and 4.5 - water.
Let X be the amount to water added to bring down the alcohol level to 30%. Then,
[(X + 4.5)/ (9 + X) ] * 100 = 30
This way, i get a negative value for X. Where am i going wrong? Someone please help
