### Brain Teasers

# Cow Cash

A farmer with seven daughters is budgeting the food and medical expenses they will incur to care for their herd of cows over a two-week period. The herd consists of adult mother cows and their calves.

Each of the farmer's daughters has seven plows, each plow is pulled by seven mother cows, and each mother cow has seven calves.

The farmer and his daughters know the following:

Out of all those mother cows, two-sevenths are still nursing their calves, while five-sevenths of the mothers have weaned their calves.

Nursing mothers eat more, so they each need 8 ounces of solid cow food a day. The other mothers need only 6 ounces a day.

The weaned calves each need 2 ounces of food a day, while the calves still being nursed don't eat any solid food.

The family pays $1.02 per pound of solid cow food.

During this two-week period, each calf has to be vaccinated. The cost of the vaccination is $14 per calf.

What will be the total amount paid to feed and vaccinate the cows during this two-week period?

Each of the farmer's daughters has seven plows, each plow is pulled by seven mother cows, and each mother cow has seven calves.

The farmer and his daughters know the following:

Out of all those mother cows, two-sevenths are still nursing their calves, while five-sevenths of the mothers have weaned their calves.

Nursing mothers eat more, so they each need 8 ounces of solid cow food a day. The other mothers need only 6 ounces a day.

The weaned calves each need 2 ounces of food a day, while the calves still being nursed don't eat any solid food.

The family pays $1.02 per pound of solid cow food.

During this two-week period, each calf has to be vaccinated. The cost of the vaccination is $14 per calf.

What will be the total amount paid to feed and vaccinate the cows during this two-week period?

### Answer

It costs $38,686.97 to care for the cows for 2 weeks.Explanation

Determine the number of cows and calves.

7 daughters x 7 plows for each daughter = 49 plows altogether

7 mother cows per plow x 49 plows = 343 mother cows

7 calves per mother cow x 343 mother cows = 2,401 calves

Determine the number of types of cows and calves.

The nursing mothers = 2/7 x 343 = 98.

The mothers with weaned calves = 5/7 x 343 = 245.

Five-sevenths of the calves are weaned and do need solid food: 5/7 x 2,401 = 1,715 weaned calves.

Two-sevenths of the calves are still nursing and don't need solid food: 2/7 x 2,401 = 686 nursing calves.

Determine the amount of food each type of cow or calf requires.

Each nursing mother needs 8 ounces of food per day; the total number of ounces of food per day for all nursing cows is: 8 x 98 = 784 oz per day.

Each mother with weaned calves needs 6 ounces of food per day; the total number of ounces of food per day for all mother cows with weaned calves is: 6 x 245 = 1,470 oz of food per day.

Weaned calves eat 2 ounces of food per day: 1,715 x 2 = 3,430 oz of food per day.

Determine the amount of food the entire herd needs.

The whole herd of cows needs:

784 + 1,470 + 3,430 = 5,684 oz

5,684 oz of food per day /16 oz per lb = 355.25 lbs of cow food per day.

Determine how much money the food will cost.

There are 14 days in 2 weeks. Multiply 355.25 lbs by 14 days to find the number of pounds of food needed for 2 weeks, 4,973.5 lbs.

Since the food costs $1.02 per pound, multiply 4,973.5 lbs. by $1.02 to find the total amount needed for food, $5.072.97.

Determine how much the vaccinations will cost.

All 2,401 calves need vaccinations. Multiply 2,401 calves by $14 per shot to find the total amount needed for shots, $33,614.

Add the cost of the food to the cost of the vaccinations to find the total cost of caring for the cows for 2 weeks.

$5,072.97 + $33,614 = $38,686.97.

Hide Answer Show Answer

## What Next?

View a Similar Brain Teaser...

If you become a registered user you can vote on this brain teaser, keep track of which ones you have seen, and even make your own.

### Solve a Puzzle

Comments hidden to avoid spoilers.

## Follow Braingle!