Evil Word Problems...

[krissimouse]

I have this one problem where it is set for me to find the amount using a simple interest formula.

A church building fund has invested some money in two ways: part of the money at 4% interest and four times as much at 3.5%. Find the amount invested at each rate if the total annual income from the interest is $3600.

**Now here's what I have done already, I have created a table listing the properties of the problem that I need to plug in, but how do I plug it all in?? I figured that instead of the normal formula to find the interest, (I=prt), but rather (p=I/rt)

I don't know if this is correct or not. Please help! Thank you!

Krissina

 

[Deleted member 4993]

I have this one problem where it is set for me to find the amount using a simple interest formula.

A church building fund has invested some money in two ways: part of the money at 4% interest and four times as much at 3.5%. Find the amount invested at each rate if the total annual income from the interest is $3600.

**Now here's what I have done already, I have created a table listing the properties of the problem that I need to plug in, but how do I plug it all in?? I figured that instead of the normal formula to find the interest, (I=prt), but rather (p=I/rt)

I don't know if this is correct or not. Please help! Thank you!

Krissina

Table won't help you here.

For all word problems - you have to first name variables.

What are they looking for?

Find the amount invested at each rate

let

the amount invested at 3.5% be = T

the amount invested at 4% be = F

What else do we know?

four times as much at 3.5%

Then

T = 4*F......................................(1)

We know

Income from T in one year = T * 3.5/100

Income from F in one year = F * 4.0/100

We also want:

total annual income from the interest is $3600

Then

T * 3.5/100 + F * 4.0/100 = 3600.......................................(2)

using (1) in above

4*F * 3.5/100 + F * 4.0/100 = 3600

Now solve for F from above

Then use (1) to find 'T'

Then check your answer by using these values of 'F' & 'T' in (2) and make sure you got satisfy the condition.

And you are done...