## anonymous 3 years ago Example A jeweler is using an alloy, a mixture of metals. He has 10 pounds of the alloy. 2% is the rare metal robium. He has another source which is 5% robium. He wishes to combine these mixtures to form a mixture that is 3% robium. Solution: 1. Identify the variables. (0.02)(10) The quantity of robium in material 1 (5%)(x) The quantity of robium in material 2 (0.03)(x+10) The quantity of the desired mixture 2. Write an equation. 5% x + (0.02)(10) = (0.03)(x+10) The equation required. 3. Perform the Solution. 0.05x + 0.2 = .03x + 0.3 = 0.02x = 0.1 4. Write the answer. x = 5 The desired amount.

1. anonymous

And i need help with these problem. An alloy of tin is 15% tin and weighs 20 pounds. A second alloy is 10% tin. How much (to the nearest tenth lb.) of the second alloy must be added to the first alloy to get a 12% mixture. ______ pounds

2. anonymous

(0.15)(20) (10%)(x) (0.12)(x+20)

3. anonymous

so far right???

4. anonymous

yess :)

5. anonymous

so next 10%x(0.15)(20)=(0.12)(x+20) right

6. anonymous

yess. seems like you have it figured out.

7. anonymous

im confuse on last part

8. anonymous

What do you need now Claire?

9. anonymous

perform the solution

10. anonymous

hrmmm i got .7 ?

11. anonymous

you mean solve the following: $.1x(.15)(.20)=(.12)(x+20)?$

12. anonymous

.10x+3=.12x+2.4=

13. anonymous

.10=.1 its 10, you don't need the 0, but it could be easier. to solve. $.1x+3=.12x+2.4$$.1x+.6=.12x$$.6=.11x$$x=1.833\infty(3)$

14. anonymous

so how did you get .6

15. anonymous

.06* my bad 1 sec. $.1x+.06=.12x$[\.06=.11x\]$1.833\infty(3)=x$ oddly,its the same answer.

16. anonymous

1.8 pounds???

17. anonymous

you could always use the percent bar method. that's easiest.

18. anonymous

so im confused how many pounds.

19. anonymous

A jeweler is using an alloy, a mixture of metals. He has 10 pounds of the alloy. 2% is the rare metal robium. He has another source which is 5% robium. He wishes to combine these mixtures to form a mixture that is 3% robium. |dw:1349373397808:dw|

20. anonymous

And i need help with these problem. An alloy of tin is 15% tin and weighs 20 pounds. A second alloy is 10% tin. How much (to the nearest tenth lb.) of the second alloy must be added to the first alloy to get a 12% mixture. ______ pounds

21. anonymous

i really hate percents just so you know. lol but ill help. just post ina new question, and don't forget to givethe best response medal.

22. anonymous

i will give bunch of them if you help me lol