a pharm tech needs to prepare 100g of 3% cream using 1%and 5%base.how much grams of each are required to compound this medication.

Question

i know its an alligation. the formula given earlier did not give me the co
rrect answer.
choices are
60gof1%40gof5%
70gof 1% 30g of 5%
50gof 1% 50g of 5%
75gof 1% 25g of 5% me
please help

Answer 1

To solve this using alligation, we can set up a chart like this:

1% | | 5%
--------|-------|--------
| 3% |
--------|-------|--------
x | 100-x |

We know we need a total of 100g of 3% cream, and we want to find out how much of the 1% and 5% bases we should mix together. Let's call the amount of 1% base we need "x". Then the amount of 5% base we need is 100-x (since the two amounts must add up to 100).

Now we can fill in the chart with the concentrations of the bases (1% and 5%) and the desired concentration of the cream (3%). We draw arrows from the 1% and 5% columns to the 3% column, and label the arrows with the difference between the concentrations (in this case, 2% and 2% since we are moving 2 percentage points away from each of the bases).

1% | | 5%
--------|-------|--------
| 3% |
--------|-------|--------
x | 100-x | (difference: 2%)
--------|-------|--------
| | (difference: 2%)

Now we can find the ratio of 1% to 5% base by dividing the length of the arrow coming from the 1% column by the length of the arrow coming from the 5% column. This gives us:

x/(100-x) = 2/2

Simplifying:

x/(100-x) = 1

x = 100-x

2x = 100

x = 50

So we need 50g of 1% base and 50g of 5% base to make 100g of 3% cream. Therefore, the answer is:

50g of 1% and 50g of 5% (option C)