Q. 1.20 - An Introduction to General, Organic, and Biological Chemistry

Question

a. At a local hospital, $35$ babies were born. If $22$were boys, what percentage of the newborns were boys? Express your answer to the one's place.

b. An alloy contains $67 g$ pure gold and $35 g$ pure zinc. What is the percentage of zinc in the alloy? Express your answer to the one's place.

c. A collection of coins contains  $15$  pennies, $14$ dimes, and 6 quarters. What is the percentage of pennies in the collection? Express your answer to the one's place.

Step-by-Step Solution

Answer

a. The percentage of the newborns were boys is 63%

b. The percentage of zinc in the alloy is 34%.

c. The percentage of pennies in  collection is 43% .

Part (a) step 1: Given Information

We need to find the percentage of the newborns were boys.

Part (a) step 2: Simplify

Here,

$$\begin{gathered} percentage=\frac{number of boys}{number of total born}\times 100 \\ percentage of boys=\frac{22}{35}\times 100 \\ =62.58\% \end{gathered}$$

Part (b) step 1: Given Information

We need to find the percentage of zinc in the alloy.

Part (b) step 2: Simplify

Now,

$$\begin{gathered} percentage=\frac{math}{total math}\times 100 \\ percentage of zinc=\frac{35}{35+67}\times 100 \\ =34.31\% \end{gathered}$$

Part (c) step 1: Given Information

We need to find the percentage of pennies in the collection.

Part (c) step 2: Simplify

Here finding the $\%$ pennies:

compute for the total number of coins: 

$15+14+6=35 coins$

determine the $\%$ pennies :

$$\begin{gathered} \%pennies=\frac{(no. of pennies)}{(no. of coins)}\times 100 \\ =\frac{15}{35}\times 100 \\ =0.429\times 100 \\ =42.9\% \end{gathered}$$