SI Formula Based MCQ Quiz - Objective Question with Answer for SI Formula Based - Download Free PDF

Given:

Principal (P) = Rs. 1,000

Rate of Interest (R) = 5% per annum

Interest is added to the principal every 10 years

Final Amount (A) = Rs. 2,000

Formula Used:

Simple Interest (SI) = P × R × T / 100

Calculation:

For the first 10 years:

SI₁ = 1000 × 5 × 10 / 100

SI₁ = 500

Amount after 10 years = Principal + SI₁

Amount₁ = 1000 + 500

Amount₁ = 1500

For the next 10 years:

Principal for the next 10 years = Amount₁

SI₂ = 1500 × 5 × 10 / 100

SI₂ = 750

Amount after 20 years = Principal + SI₂

Amount₂ = 1500 + 750

Amount₂ = 2250

Since Amount₂ (Rs. 2250) exceeds Rs. 2000, we need to find the exact time when it becomes Rs. 2000.

Let the time required after the first 10 years be T years to reach Rs. 2000:

SI = 1500 × 5 × T / 100

Interest needed = 2000 - 1500 = 500

⇒ 1500 × 5 × T / 100 = 500

⇒ 75T = 500

⇒ T = 500 / 75

⇒ T = 6 (2/3) years

Total time = 10 + 6 (2/3) years

Total time = 16 (2/3) years

Therefore, the correct answer is option 4: 16 (2/3) years.

Given:

Principal (P) = ₹ 9,500

Simple Interest (SI) = ₹ 1,520

Time (T) = 4 years

Formula Used:

Simple Interest (SI) = (P × R × T) / 100

where P → Principal, R → Rate of Interest, T → Time

Calculations:

According to Question:

1,520 = (9,500 × R × 4) / 100

1,520 = 38,000R / 100

1,520 = 380R

R = 1,520 / 380

R = 4%

∴ The rate of interest per annum is 4%.

Given:

Principal (P) = Rs. 6,000

Rate of interest (R) = 10% p.a.

Final amount (A) = Rs. 28,000

Formula Used:

Simple Interest (SI) = (P × R × T) / 100

Amount (A) = Principal + Interest

Calculation:

Since the interest is added to the principal after every 20 years, we need to find the time (T) in years where the amount becomes Rs. 28,000.

First 20 years:

SI₁ = (6000 × 10 × 20) / 100

⇒ SI₁ = 12000

New Principal after 20 years = P + SI₁

New Principal = 6000 + 12000 = 18000

SI₂ = 28000 - 18000 = 10000

SI₂ = (18000 × 10 × T)/100

⇒ 10000 = (18000 × 10 × T)/100

⇒ 10000/1800 = T

⇒ T = 5.55 years.

Total Time = 20 years + 5.55 years = 25.55 years

The correct answer is option 3.

Given:

Principal (P₁) = ₹5,000

Rate (r₁) = 4% per annum

Principal (P₂) = ₹8,000

Rate (r₂) = 8% per annum

Time (t₂) = \(2 \frac{1}{2}\) years = 5/2 years

Formula used:

Simple Interest (SI) = \(\frac{P \times r \times t}{100}\)

Calculations:

Interest from ₹8,000 = \(\frac{8000 \times 8 \times \frac{5}{2}}{100}\)

⇒ \(\frac{8000 \times 8 \times 5}{2 \times 100} = 1600\)

So, interest = ₹1,600

Now, we need the interest from ₹5,000 to be ₹1,600.

Interest from ₹5,000 = \(\frac{5000 \times 4 \times t_1}{100}\)

⇒ \(\frac{5000 \times 4 \times t_1}{100} = 1600\)

⇒ \(\frac{20000 \times t_1}{100} = 1600\)

⇒ \(\frac{20000 \times t_1}{100} = 1600 \Rightarrow 200 \times t_1 = 1600\)

⇒ \(\Rightarrow t_1 = \frac{1600}{200} = 8\)

Answer:

Time (t₁) = 8 years

Given:

Amount (A) = ₹21,420

Time (T) = 2 years

Rate (R) = 9.5% p.a.

Formula Used:

Simple Interest (SI) = (P × R × T) / 100

Amount (A) = Principal (P) + Simple Interest (SI)

Calculation:

Let the principal be P.

Simple Interest (SI) = (P × 9.5 × 2) / 100

SI = 0.19P

Amount (A) = P + SI

⇒ 21,420 = P + 0.19P

⇒ 21,420 = 1.19P

⇒ P = 21,420 / 1.19

⇒ P = 18,000

The principal is ₹18,000.

Given:

Principle = Rs. 2700

Time = 8 months = 8/12 year = 2/3 year

Rate of interest = 5 paisa per month = 5 × 12 paisa per year = 60 paisa per year = 60 %

Formula used:

SI = PRT/100

Calculation:

SI = (2700 × 60 × 2) / (100 × 3)

⇒ 9 × 120

⇒ 1080

∴ The SI will be Rs. 1080.

Given : 

Principal = Rs.78000

Time = 146 days

Rate = 35/4 %

Formula Used : 

SI = (P × R × T)/100

Calculation : 

Jan. = 8 days 

Feb. = 29 days

March = 31 days

April = 30 days

May = 31 days

June = 17 days ----(not 18 because she paid it back on 18th June)

So, 8 + 29 + 31 + 30 + 31 + 17 = 146 days

⇒ SI = 78000 × 35/4 × 146/366 × 1/100

⇒ SI = 3985800/1464 = 2722.54098

Amount = 78000 + 2722.54098 = 80722.541

Amount = Rs.80723

∴ The correct answer is Rs.80723.

Given:

Amount (A) = Rs. 1,100

Time(T) = 2 years

Rate of simple interest per annum(R) = 5%

Formula used:

Simple interest(SI) = (P × R × T) / 100

SI = A - P

Calculation:

Let, P = principal.

As per the question,

⇒  1100 - P =  (P × 5 × 2) / 100 

⇒  1100 - P =  P /10

⇒ 11P/10 = 1100

⇒ 11P = 11000

⇒ P = Rs 1000

∴ The correct option is 3

Given:

The interest earned on Rs. 21,000 in 3 years at simple interest is Rs. 6,400

Concept used:

S.I = P × R × T / 100

( P = Principal , R = Rate of interest, T = Time)

Calculation:

S.I =6400

As per formula 

6400  = 21000  × R × 3 / 100

⇒ R =6400/630

⇒ R =10\(\frac{10}{63}\)%

∴ The correct option is 4

Given:-

Principal (P) = ₹27,000

The rate (R) = 44/3% per annum,  

Time (T) =  8 months = (8/12)year

Formula used:- 

Simple Interest (SI) = (Principal  × Rate  ×Time) / 100

Calculation:-

SI = (27000 × 44 × 8)/ (3 × 12 ×100)  

⇒ SI = 60 × 44 = 2640 Rs.  

∴ The required answer is 2640.

Given:

On simple interest, a sum of Rs. 6400 becomes Rs. 8320 in 3 years.

Concept used:

S.I = (P × T × R)/100

P = Sum

T = Time

R = Rate

Calculation:

Interest for 3 years = 8320 - 6400

⇒ 1920

Let the interest be x%

Now,

1920 = (6400 × 3 × x)/100

⇒ 192x = 1920

⇒ x = 10

Now,

S.I = (P × T × R)/100

= (7200 × 5 × 10)/100

⇒ 3600

So, amount = 7200 + 3600

⇒ 10800

∴ The required answer is Rs. 10800.

Given:

Principal = Rs. 10200

Rate = 12.5 %

A = Rs. 19125

Time period = ?

Formula used:

Simple interest = \(P \times R \times T \over 100\) 

where P = Principal amount

R = Rate

T = Time period

S.I. = A - P

Calculation:

S.I. = 19125 - 10200 = 8925

S.I.  = \(10200 \times 12.5 \times T \over 100\)

8925 = \(10200 \times 12.5 \times T \over 100\)

T = \(8925 \times 100 \over 10200 \times 12.5\)

⇒ 7 years

∴ The time in which a sum of Rs. 10200 amounts to Rs. 19125 at the rate of 12.5 percent per annum at simple interest is 7 years.

Given:

Sum = Rs. 5250

Amount = Rs. 9870

Rate = 11%

Concept used:

S.I = (P × T × R)/100

Here,

P = Sum

T = Time 

R = Rate

Amount = Sum + S. I

Calculation:

Interest = 9870 - 5250

⇒ 4620

Now,

Let the time be T years

4620 = (5250 × T × 11)/100

⇒ 420 = 210T/4

⇒ T = 4 × 2 = 8

So, time is 8 years

∴ The required time is 8 years.

Given:

A person invests Rs. 9,840 at 5% per annum simple interest to obtain a total amount of Rs. 12,300

Formula used:

Simple interest = P × R × T / 100 [ P = principal, R = rate of interest, T = time]

Calculation:

Let,T = time 

Simple interest got by the person is 12300 - 9840 = Rs 2460

As per the formula,

 2460 = 9840 × 5 × T / 100

⇒ T = 2460 /492

= 5 years

∴ The correct option is 1

Given:

Principal = Rs.9000

Amount = Rs.10200

Time = 4 years

Formula used:

Simple interest (S.I) = (P × R × T)/100

Amount (A) = (S.I + P)

Where, P = principal; R = rate; T = time

Calculation:

Simple interest (S.I) = (A - P)

⇒ (10200 - 9000) = Rs.1200

Rate = (1200 × 100)/(9000 × 4)

⇒ (10/3) = 3\(1\over3\) %

∴ The correct answer is 3\(1\over3\) %.