Question

grade 5 word problems worksheet
an aquarium has exhibits that feature different marine animals.

1. 5/8 of the staff are male. 5/12 of the staff works part - time at the aquarium. what fraction of the staff is female?
2. the sharks are fed three times a day. during the morning feeding, 2/15 of a ton of fish is fed. during the afternoon feeding, the weight of fish fed will be 1/15 of a ton more than the fish fed during the morning. if the total weight of fish fed in a day is 1/2 of a ton, how much is fed during the feeding at night?
3. a baby otter was born 3/4 of a month early. at birth, its weight was 7/8 kilograms, which is 9/10 kilogram less than the average weight of newborn otter in the aquarium. what is the average weight of newborn otter?

Explanation:

Step 1: Determine the whole

The whole of the staff is represented by 1.

Step 2: Subtract the fraction of male staff

We know that $\frac{5}{8}$ of the staff are male. To find the fraction of female staff, we subtract the fraction of male staff from 1. So, $1-\frac{5}{8}=\frac{8}{8}-\frac{5}{8}=\frac{8 - 5}{8}=\frac{3}{8}$.

Step 1: Find the amount of fish fed in the afternoon

During the morning feeding, $\frac{2}{15}$ of a ton of fish is fed. During the afternoon feeding, the weight of fish fed is $\frac{1}{15}$ of a ton more than the morning feeding. So the amount of fish fed in the afternoon is $\frac{2}{15}+\frac{1}{15}=\frac{2 + 1}{15}=\frac{3}{15}=\frac{1}{5}$ of a ton.

Step 2: Calculate the total amount of fish fed in the morning and afternoon

The total amount of fish fed in the morning and afternoon is $\frac{2}{15}+\frac{1}{5}=\frac{2}{15}+\frac{3}{15}=\frac{2+3}{15}=\frac{5}{15}=\frac{1}{3}$ of a ton.

Step 3: Find the amount of fish fed at night

The total weight of fish fed in a day is $\frac{1}{2}$ of a ton. To find the amount of fish fed at night, we subtract the total amount of fish fed in the morning and afternoon from the total amount fed in a day. So, $\frac{1}{2}-\frac{1}{3}=\frac{3}{6}-\frac{2}{6}=\frac{3 - 2}{6}=\frac{1}{6}$ of a ton.

Step 1: Set up the equation

Let the average weight of a newborn otter be $x$ kilograms. We know that the weight of the baby otter which was born early is $\frac{7}{8}$ kilograms and it is $\frac{9}{10}$ kilogram less than the average weight. So the equation is $x-\frac{9}{10}=\frac{7}{8}$.

Step 2: Solve for $x$

To solve for $x$, we add $\frac{9}{10}$ to both sides of the equation. $x=\frac{7}{8}+\frac{9}{10}$. First, find a common - denominator, which is 40. Then $\frac{7}{8}=\frac{7\times5}{8\times5}=\frac{35}{40}$ and $\frac{9}{10}=\frac{9\times4}{10\times4}=\frac{36}{40}$. So $x=\frac{35}{40}+\frac{36}{40}=\frac{35 + 36}{40}=\frac{71}{40}=1\frac{31}{40}$ kilograms.

Answer:

$\frac{3}{8}$