How much pure alcohol should be added to 25litres of 16% alcohol to increase the concentration to 60%.

Question

1. A certain obstetrican found the 9o% of babies she delivered weighed x pound where /x-8.5/ less than equal to 1. Determine the range of weight that correspounds to the inequality

 

2. sixty-six times the absolute value of a negative number is 134938 more than the number. find the number.

 

3.christy needs 10% hydrochloric acid for an organic chemistry experiment. how much 5% acid should she mix with 60millitres of 20% acid to abtain a 10% solution.

 

4. How much pure alcohol should be added to 25litres of 16% alcohol to increase the concentration to 60%.

 

5.A pharmacist wishes to strengthen  a mixture from 10% alcohol to 30% alcohol. Determine how much pure alcohol should the pharmacist  add to 15 litres of the 10% mixture.

6. find the equation of a line -x+y+7=0

Answer 1

.16(25)+x= .6(25+x)=15+.6x

.4x=11

x=110/4=27.5 liters pure alcohol to get 52.5 liters of 60%

.16(25)+27.5 =.6(52.5)=31.5