Who can answer these equations?

[softpigeon]

1. Mr. Morgan invested $20,000 in an account earning with 4.5% interest. How many years would it take to earn $5,400 in simply interest?


2. Kathryn bought an aquarium to replace her fish bowl. The directions of the aquarium are that it should be filled with 9 cubic feet of water. If it is 2 feet wide, and 3 feet long, how high should the water fill the aquarium?
Hint: V=lwh


3. Mary and her father went on an all-day ride in the car. They traveled 3 times as far in the after noon as they did in the morning. At the end of the day, they traveled 420 miles. How far did they travel in the morning?


MIXTURE PROBLEM
4. George runs a candy stand at the downtown market. He sold jelly beans at $4 per pound and chocolate at $7 per pound. If he sells 10 more pounds of jelly beans than chocolate bars, he will make $260. How many pounds of jelly beans did George sell?

 

[Deleted member 4993]

1. Mr. Morgan invested $20,000 in an account earning with 4.5% interest. How many years would it take to earn $5,400 in simply interest?


2. Kathryn bought an aquarium to replace her fish bowl. The directions of the aquarium are that it should be filled with 9 cubic feet of water. If it is 2 feet wide, and 3 feet long, how high should the water fill the aquarium?
Hint: V=lwh


3. Mary and her father went on an all-day ride in the car. They traveled 3 times as far in the after noon as they did in the morning. At the end of the day, they traveled 420 miles. How far did they travel in the morning?


MIXTURE PROBLEM
4. George runs a candy stand at the downtown market. He sold jelly beans at $4 per pound and chocolate at $7 per pound. If he sells 10 more pounds of jelly beans than chocolate bars, he will make $260. How many pounds of jelly beans did George sell?

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[stapel]

You posted these to "Pre-Algebra", thereby telling us that you haven't yet studied algebra. Have you done anything with "variables" or "formulas" (equations with letters in them) at all?

1. Mr. Morgan invested $20,000 in an account earning with 4.5% interest. How many years would it take to earn $5,400 in simply interest?

Are you familiar with how to find a given percentage of a given amount? If so, then try finding 4.5% of $20,000. This is the amount of (simple) interest earned in one year.

How many years are required to earn $5,400? (Hint: Divide.)

2. Kathryn bought an aquarium to replace her fish bowl. The directions of the aquarium are that it should be filled with V = 9 cubic feet of water. If it is w = 2 feet wide, and L= 3 feet long, how high h should the water fill the aquarium? Hint: V=Lwh

From the "hint", it seems safe to assume that, yes, you have had exposure to at least some elementary algebra; namely, you have seen variables and formulas.

Use the formula they gave you: Plug the given numbers into the given equation. Then solve (that is, divide through) to get the number for the letter that remains.

3. Mary and her father went on an all-day ride in the car. They traveled 3 times as far in the after noon as they did in the morning. At the end of the day, they traveled 420 miles. How far did they travel in the morning?

For every morning mile, they had three afternoon miles. In other words, their miles can be viewed as coming in sets of four. How many sets of four are in "420"? (Hint: Divide.) Since each set of four contained one morning mile, how many morning miles were there?

4. George runs a candy stand at the downtown market. He sold jelly beans at $4 per pound and chocolate at $7 per pound. If he sells 10 more pounds of jelly beans than chocolate bars, he will make $260. How many pounds of jelly beans did George sell?

This exercise is ill-formed; it is not solvable with only the given information. For instance:

. . . . .0 lbs choco, 10 lbs beans: $0 + $40 = $40, not $260

. . . . .10 lbs choco, 20 lbs beans: $70 + $140 = $210, not $260

. . . . .50 lbs choco, 60 lbs beans: $350 + $240 = $590, not $260

So we can easily find loads of "if he sells ten more pounds of beans than choco bars" where he does not "make $260". Please consult with your instructor regarding correction and clarification.

When you reply, please include a clear listing of your thoughts and efforts so far, so we can see what's going on and where you're needing help. Thank you!

 

[HallsofIvy]

I am puzzled by stapel's remarks on the last one. Yes, there are loads of "if he sells ten more pounds of beans than choco bars" where he does not "make $260" but only one where he does and that was what was asked.

4. George runs a candy stand at the downtown market. He sold jelly beans at $4 per pound and chocolate at $7 per pound. If he sells 10 more pounds of jelly beans than chocolate bars, he will make $260. How many pounds of jelly beans did George sell?

Okay this is a little confusing! I presume the "chocolate at $7 a pound" and "chocolate bars" refer to one pound chocolate bars (as sold at "Trader Joes").

Let "x" be the number of chocolate bars he sold. Then he sold 10+ x pounds of Jelly beans and made 4(10+ x)+ 7x= 40+ 4x+ 7x= 40+ 11x = 260. Solve that for x, the number of chocolate bars and add 10 to find the number of pounds of Jelly beans sold.