Simple interest rate is given by:
I=(PRT)/100
let the amount invested in 5% S.I. be $x and amount invested in 6% S.I. be $(8000-x)
Interest obtained from 5% will be:
I=5/100×1×x=0.05x
Interest obtained from 6% will be:
I=6/100×1×(8000-x)=0.06(8000-x)
therefore total interest earned from the to schemes will be:
0.05x+0.06(8000-x)=438
solving for x we obtain:
0.05x+480-0.06x=438
0.05x-0.06x=438-480
-0.01x=-42
x=-42/(-0.01)
x=$4200
hence amount invested in 5% S.I. is $4200 and amount invested in 6% S.I. is (8000-4200)=$3800
Answer:
The first two is 3
The first three is 6
The first four is 10
The first five is 15
The first six is 21
I don't know the last one lol
