Question

15. In how many years will a sum of 2,000 amount to
1
2,315 at 45 per annum ?
2
(B) 4 years
(A) 3 years
1
(C) 35 years
(D) 5 years​

Answer 1

Answer:

Given :-

• Principal = Rs 2000
• Amount = Rs 2315
• Rate of Interest = 45%

Formula Used :-

❶To find Simple Interest we know that,

$\boxed{\bold{\large{S.I\: =\: A\: -\: P}}}$

where,

• S.I = Simple Interest
• A = Amount
• P = Principal

❷To find time, we know that,

$\boxed{\bold{\large{t\: =\: \dfrac{S.I\: \times 100}{p \times r}}}}$

where,

• t = Time
• S.I = Simple Interest
• p = Principal
• r = Rate of Interest

Solution :-

❶ First we have to find the Simple Interest,

Given :

• Principal = Rs 2000
• Amount = Rs 2315

According to the question by using the formula we get,

↦ S.I = Rs 2315 - Rs 2000

➠ S.I = Rs 315

❷ Now we have to find the time,

Let, the time be t years

Given :

• S.I = Rs 315
• Principal = Rs 2000
• Rate of Interest = 45%

According to the question by using the formula we get,

⇒ t = $\sf\dfrac{315 \times 100}{2000 \times 45}$

⇒ t = $\sf\dfrac{31500}{90000}$

⇒ t = $\sf\dfrac{\cancel{31500}}{\cancel{90000}}$

➦ t = 0.35 years

$\therefore$ In 0.35 years the sum of Rs 2000 amount to Rs 2315 at 45% per annum.