Question

4. *Find the rate percent(R) In the following problems*
(i) P= 400 S.I= 60 T=4 years
(ii) P=600 S.I=150 T=5 years​

Answer 1

1st Answer

We can find the rate of interest by the formula of simple interest.

$\sf \dashrightarrow SI = \dfrac{P \times R \times T}{100}$

$\sf \dashrightarrow 60 = \dfrac{400 \times R \times 4}{100}$

$\sf \dashrightarrow 60 = \dfrac{1600 \times R}{100}$

$\sf \dashrightarrow 60 = \dfrac{1600R}{100}$

$\sf \dashrightarrow R = \dfrac{60 \times 100}{1600}$

$\sf \dashrightarrow R = \dfrac{60 \times 1}{16}$

$\sf \dashrightarrow R = \dfrac{60}{16}$

$\sf \dashrightarrow R = \dfrac{15}{4} = 3.75\%$

Hence, the rate of interest is 3.75%.

2nd Answer

$\sf \dashrightarrow SI = \dfrac{P \times R \times T}{100}$

$\sf \dashrightarrow 150 = \dfrac{600 \times R \times 5}{100}$

$\sf \dashrightarrow 150 = \dfrac{3000 \times R}{100}$

$\sf \dashrightarrow 150 = \dfrac{3000R}{100}$

$\sf \dashrightarrow R = \dfrac{150 \times 100}{3000}$

$\sf \dashrightarrow R = \dfrac{1 \times 100}{20}$

$\sf \dashrightarrow R = \dfrac{100}{20} = 5\%$

Hence, the rate of interest is 5%.

Answer 2

Answer:

(i) The rate percent is 3.75%.

(ii) The rate percent is 5%.

Step-by-step explanation:

(i) P= 400 S.I= 60 T=4 years

We know that, the simple interest formula, which says:

→ SI=P*R*T/100

→ 60=400*R*4/100

→ 60=4*R*4

→ 60=4*4*R

→ 60=16*R

→ R=60/16

→ R=3.75%

Hence, the rate percent is 3.75.

(ii) P=600 S.I=150 T=5 years

We know that, the simple interest formula, which says:

→ SI=P*R*T/100

→ 150=600*R*5/100

→ 150=6*R*5

→ 150=6*5*R

→ 150=30*R

→ R=150/30

→ R=5%

Hence, the rate percent is 5%.