I need help solving these two problems.
1)How many liters of water should be evaporated from 160liters of a 12% saline solution so that the solution that remains is a 20% saline solution?
2)Printer A can print a report in 3 hours, printer B can print the same report in 4 hours. How long will it take both printers working together, to print the report?
2007-02-22 14:50:05 · 5 answers · asked by midnightjoker 5 in Education & Reference ➔ Homework Help
First find a common denominaor..which i used 12 (4 and 3 both go into 12). If printer A can print 12 pages in 3 hours, that is 4 pages per hour. Printer B prints 12 pages in 4 hours, that is 3 pages per hour. Together, they print 7 pages an hour. 1/7 = x/12 which by using cross multiplying and dividing should equal 1.714 hours. I think that is right!!!
2007-02-22 15:02:08 · answer #1 · answered by blix2576 1 · 0⤊ 0⤋
If you have 160 liters of saline solution I'd think about it this way. 20% is how many liters? 12% is how many litters? So what is the difference from how much you want to be saline from saline soltution that you presently have in liters? So take that 8% which is 12.8 in liters and subtract from 160 liters. That should be the remainimg liters you take off in liquid. ???? Your answer in liters should be less of course than 160 which you had to start with. I can give you the answer, but it's your homework. Now figure out the formula.
2007-02-22 23:50:27 · answer #2 · answered by Anonymous · 0⤊ 0⤋
1)
160/12 = x/20
3200=12x
x=266.6 L
2007-02-22 23:14:27 · answer #3 · answered by katie 2 · 0⤊ 0⤋
sorry, but i can only answer 2 which is 12 hours
2007-02-22 22:59:34 · answer #4 · answered by arzbarz 2 · 0⤊ 0⤋
2) it would be one hour....the difference of two printers working together
2007-02-22 22:57:39 · answer #5 · answered by mrs_b40 3 · 0⤊ 1⤋