# Thread: [SOLVED] Need help with word problem

1. ## [SOLVED] Need help with word problem

Please help. I am not sure how to figure this out.
Thanks.

A silversmith mixed 25g of a 70% silver alloy with 50 grams of a 15% silver alloy What is the percent concentration of the resulting alloy?

A hospital staff member mixed a 65% disinfectant solution with a 15% disinfectant solution. How many leaders of each were used to make 50L of a 40% disinfectant solution?

A jeweler mixed 15g of a 60% silver allow with 45g of a 20% silver allow. What is the percent concentration of silver in the resulting alloy?

A 750ml solution is 4% hydrogen peroxide. How much more hydrogen peroxide is in a 850ml solution that is 5% hydrogen peroxide?

2. Originally Posted by earlene2
Please help. I am not sure how to figure this out.
Thanks.

A silversmith mixed 25g of a 70% silver alloy with 50 grams of a 15% silver alloy What is the percent concentration of the resulting alloy?
To find precentage you need to use formula,
$\displaystyle \mbox{concentration}=\frac{\mbox{amount of silver}}{\mbox{total amount}}$
Thus, since you have 70% of 25 grams (.7)25=17.5 grams of silver. Since, you have 15% of 50 grams you have 7.5 grams. Thus, a total of 25 grams. To find the precentage,
you have $\displaystyle \frac{25}{75}$ which is 33%.