help calculating a total investment

Question

equal investments are invested at 6%,7%, and 8% annual interests. if the three total investments yield a total of $2037, find the total investment

Answer 1

Let every  Investment = $ x

 

Yield on 6% investment = 0.06* x =0.06x

 

Yield on 7% investment = 0.07* x =0.07x

 

Yield on 8% investment = 0.08* x =0.08x

 

three total investments yield a total of $2037

 

0.06x +0.07x +0.08x =2037

 

0.21 x =2037

 

x = 2037 /0.21

 

x = 9700

 

So toatl investment= 9700 +9700+9700=29100

Answer 2

I = prt

 

If the interest totals to $2037 in 1 year then:

 

2037 = 0.06p + 0.07p + 0.08p

 

2037 = 0.21p

 

p = 2037/0.21

 

p = $9700

 

$9700 was invested at each interest rate for a total investment of

3(9700) = $29,100