College Algebra HELP!!! PLEASE!!!?

Question

I cannot figure out how to do mixture problems for the life of me. I could really use some help and explanation of how to do them. Thanks!

A bottle contains 750ml of fruit punch with a concentration of 50% pure fruit juice. Jill drinks 100ml of the punch and then refills the bottle with an equal amount of a cheaper brand of punch. If the concentration of juice in the bottle is now reduced to 48%, what was the concentration in the punch that Jill added?

Answer 1

After Jill drank 100 ml of the 50% conc juice,
650 ml of the same was left.Let the 100ml of the cheaper brand of punch that was added had x% concentration

According to the problem
0.50*650+(x/100)*100=0.48*750
=>325+x=360
x=360-325=35
therefore the second fruit juice had 35% concentration

Answer 2

Find out how much pure juice is in before and after. 50% of 750 is 375; 48% is 360. The 100 mL she drank removed 50 mL but the 100 mL she replaced only put back 35 mL since it's 15 mL weaker. So the cheaper punch was 35/100 = 35% juice.

Answer 3

Jill drinks 100 ml. Now there are 650 ml left, and there is still 50% of pure fruit juice.

She add 100 ml of differcent punch
.5(650) + (100)x = .48(750)
325 + 100x = 360
100x = 35
x = .35

the concentration in the punch that Jill added is 35%

Answer 4

Ok make a table (the columns will not line up on here):
Percent Ml mixture Ml pure fruit juice
.5 * 650 = 325
x * 100 = 100x
.48 * 750 = 360

Add the mixtures (from the last column) to get:
100x+325=360
x=.35 or 35%

Answer 5

You now have a mixture:

(750 - 100) ml = 650 ml of 50% fruit juice
100 ml of unknown% fruit juice

Total 750 ml of 48% fruit juice

650*0.50 + 100x = 750*0.48
100x = 750*0.48 - 650*0.50 = 360 - 325 = 35
x = 35/100 = 35% fruit juice

The cheaper replacement juice was 35% fruit juice.

Answer 6

360 ml.

Answer 7

35%?

Answer 8

um, cupcake??


sorry, I'm in the 8th grade.

I think it's 2% though