A druggist needs to prepare 100ml. of a 10% solution. She has available only a 5% and a 25% solution. How much of each should she use to prepare the desired solution?

25 milliliters of 25% solution and 75 milliliters of 5% solution should be used.

Step-by-step explanation:

Since the druggist has to prepare 100 ml of a 10% solution, but has only 5% and 25% solutions, to determine the proportion of each solution that he must use to prepare the solution with the desired percentage, it is necessary to perform the following calculation:

25 x 1 + 5 x 0 = 25

25 x 0.9 + 5 x 0.1 = 23

25 x 0.8 + 5 x 0.2 = 21

25 x 0.7 + 5 x 0.3 = 19

25 x 0.6 + 5 x 0.4 = 17

25 x 0.5 + 5 x 0.5 = 15

25 x 0.4 + 5 x 0.6 = 13

25 x 0.3 + 5 x 0.7 = 11

25 x 0.2 + 5 x 0.8 = 9

Therefore, the percentage that the druggist must use will be between 20% and 30% of the 25% solution, and between 70% and 80% of the 5% solution, that is:

25 x 0.25 + 5 x 0.75 = 10

Therefore, the druggist should use a 25% solution at 25%, and a 75% solution at 5%: Thus, since 100 x 0.25 is equal to 25, 25 milliliters of 25% solution and 75 milliliters of 5% solution should be used.

answer: there are x+184 pages in olivia's book.

step-by-step explanation:

let the total number of pages in the book which olive has already read be x.

then if olive has 184 pages left to read, then the total number of pages are in olive's book= pages she has read+pages she has left to read

therefore, the total number of pages in olivia's book=

hence, there are x+184 pages in olivia's book.