Question

100 gives

PRT
The simple interest formula I
the interest I on a principal P invested at a
rate of R% per annum for T years.
a Find the interest when N150 000 is
invested at 5% per annum for 4 years.
b Find the principal that gains an interest of
N16100 in 5 years at 7% per annum.​

Answer 1

`\boxed{ \bold{ \boxed{ \sf{a. \: \: interest \: = \: N \: 30000}}}}`

`\boxed{ \bold{ \boxed{ \sf{b. principal \: = \: N \: 46000}}}}`

Explanation:

a. Given,

Principal ( P ) = N 150000

Rate ( R ) = 5 %

Time ( T ) = 4 years

Interest ( I ) = ?

Finding the Interest ( I )

`\boxed{ \bold{ \sf{interest = (principal * time * rate)/(100) }}}`

⇒
`\sf{interest = (150000 * 4 * 5)/(100) }`

⇒
`\sf{interest = (3000000)/(100)}`

⇒
`\sf{interest = N \: 30000}`

Interest = N 30000

------------------------------------------------------------

b. Given,

Interest ( I ) = N 16100

Time ( T ) = 5 years

Rate ( R ) = 7 %

Principal ( P ) = ?

Finding the principal

`\boxed{ \bold{ \sf{principal = (interest * 100)/(time * rate)}}}`

⇒
`\sf{ (16100 * 100)/(5 * 7) }`

⇒
`\sf{ (1610000)/(35) }`

⇒N
`\sf{46000}`

Principal = N 46000

Hope I helped!

Best regards!!

Answer 2

Explanation:

a) P = N 150000

R = 5%

T = 5 years

Plug in the values P,R & T in the formula

I = PRT

`I=150000*(5)/(100)*4\\\\= 1500 * 5 * 4\\`

I = N 30000

b) I = N 16100

R = 7%

T = 5 years

`PRT = I\\\\P*(7)/(100)*5=16100\\\\P=16100*(100)/(7*5)`

P= N 46000