# Simple Interest Class 7 RS Aggarwal Exe-11A Goyal Brothers ICSE Maths Solutions

Simple Interest Class 7 RS Aggarwal Exe-11A Goyal Brothers ICSE Maths Solutions.  We provide step by step Solutions of lesson/ Chapter-11 Simple Interest for ICSE Class-7 Foundation RS Aggarwal Mathematics of Goyal Brothers Prakashan to develop skill and confidence. Visit official Website CISCE for detail information about ICSE Board Class-7 Mathematics.

## Simple Interest Class 7 RS Aggarwal Exe-11A Goyal Brothers ICSE Maths Solutions

 Board ICSE Publications Goyal brothers Prakashan Subject Maths Class 7th Chapter-11 Simple Interest Writer RS Aggrawal Book Name Foundation Topics Solution of Exe-11A Academic Session 2024 – 2025

### Simple Interest Imp Questions with Solutions

Class 7 RS Aggarwal Exe-11A Goyal Brothers ICSE Foundation Maths Solutions.

##### Question-1: Find the simple interest and amount on each of the following:

(i) ₹8400 for 4 years at 8% per annum.

Sol – (i)  Principal(P) = Rs. 8400,   Time(T) = 4 years,     Rate(R) = 8%

Simple Interest (SI) = PRT/100

SI = (8400×4×8) / 100

SI = 84×4×8

Hence SI = ₹ 2688.

Amount = P + SI = 8400 + 2688 = ₹11088.

Sol – (ii) ₹50000 for 3 years 12(1/2)% per annum.

Ans-(ii) Principal (P) = ₹50,000           Rate (R) = 12½ % = 25/2 %            Time (T) = 3 years

Simple Interest (SI) = PRT/100

SI = 50,000 × 25/2 × 3/100

SI = ₹18750.

Amount = P + SI = ₹50,000 + ₹18,750 = ₹68,750.

Sol – (iii) ₹9275 for 2 years at 7(1/2)% per annum.

Ans-(iii) Principal(P) = ₹ 9275       Time (T) = 2 years         Rate (R) = 7 1/2 %

Simple Interest (SI) = PRT/100

SI = (9275(2) (7 1/2))/100

= (18550) (15/2)/100

= (9275)(15)/100

Hence = ₹1391.25

Amount = P + SI = 9275 + 1391.25 = ₹10666.25

##### Question-2: In what time will ₹ 7500 amount to ₹8625, if simple interest is reckoned at 7(1/2)% per annum?

Solution:  Amount= 8625,     Principle= 7500,   Rate = 15/2%

SI = A-P = 1125

Simple Interest (SI) = PRT/100

1125=7500 * t * (15/200)

5 * 225 =5 * 15 * 15 * (t/2)

t = 2 years.

##### Question-3: In what time will ₹ 3600 amount to₹ 4320 at 4% per annum simple interest?

Solution : The amount is given as Rs4320 and the principle is given as Rs3600 with the rate of 4%. Then, the simple interest will be,

S.I.= Amount−Principle =4320−3600 =720

Now, SI = (P*R*T)/100

720=(3600*4*T)/100

T=(720*100) /(3600*4)

T=5 years.

##### Question-4: At what rate per cent per annum will ₹6300 yield an interest of ₹2100 in 4 years?

Solution : The principle is given as Rs 6300 and the simple interest is given as Rs 2100 with time as 4 years.

S.I.= (P*R*T) /100

2100=(6300*R*4 ) /100

R=(2100*100) / (6300*4)

R = (25/3)% = 8(1/3)%

##### Question-5: At what rate per cent per annum simple interest will ₹66000 amount to  ₹72720 in 2 years?

Solution:  Principal,P = Rs. 66,000, Time(T) = 2 years

S.I. = 72,720 – 66,000 = Rs. 6,720

Rate(R) = ?

S.I. = (P * R * T ) /100

R = (6720*100) / (66,000 * 2)

Rate = 5.09% = 5(1/11)% per annum.

##### Question-6: The simple interest on a sum of money for 5 years is 3/5 of the sum. Find the rate per cent per annum.

Solution: Let Rs x be the sum. Then according to the question, the simple interest will be 35x.

S.I.=(P*R*T)/100

(3/5)x=(x* R *5) /100

R=(3x * 100) / (5*x*5)

R=12% p.a.

##### Question-7:  The simple interest on a certain sum for 3 years at 10% per annum is ₹829.50. Find the sum.

Solution : The simple interest is given as Rs 829.50 with the rate of 10% per annum for 3 years

S.I.=(P*R*T) /100

829.50=(P*10 *3) /100

P=(829.50*100)/(10*3)

P=Rs 2765.

##### Question-8: What sum will yield an interest of ₹7840 in 2 years at 6(1/4) % per annum?

Solution: The simple interest is given as Rs7840 in 2 years at the rate of 254%.

S.I.=(P*R*T)/100

7840=(P * 254 * 2)/100

P=(7840*4*100)/(25*2)

P=Rs 62720.

##### Question-9: At what rate per cent per annum simple interest will a sum treble itself in 16 years?

Solution: Let Rs x be the sum, then according to question, the amount will be Rs3x. Then simple interest will be,

S.I.=Amount−Principle = 3x−x =2x

The time is given as 16 years.

S.I.=(P×R×T)/100

2x=(x × R × 16)/100

R=2x ×100x × 16

R=12.5% = 12(1/2)%.

##### Question-10: A sum when reckoned at 6% per annum simple interest amounts to ₹4130 in 3 years. Find the sum.

Solution : The amount is given as Rs4130 at the rate of 6% per annum in 3 years.

we known that,

S.I.=Amount−Principle

S.I.=4130−P ——eq(1)

And,

S.I.=(P×R×T)/100

S.I.=(P×6×3)/100 ——eq(2)

From equation (1) and (2),

⇒  4130−P=(P×6×3)/100

⇒ 4130=(18P/100)+P

So  4130=(18P+100P)/100

⇒ 413000=118P

P=413000/118

P=Rs 3500.

##### Question-11: A sum of money put at 11% per annum simple interest amounts to ₹ 10370 in 2 years. What will it amount to in 3 years at the same rate?

Solution: Let the principal be x

Amount = Rs 10370

Simple interest = Amount – Principal

Simple Interest= 10370-x

Rate of interest = 11%

Time = 2 years

Simple interest = (PRT)/100

10370-x = (x* 11 * 2 )/100

x =8500

Now we are supposed to find what will it amount to in 3 years at the same rate

Principal = Rs.8500

Time = 3 years

Rate of interest = 11%

SI =(PRT)/100

SI = (8500 * 11 *3) /100,

Hence SI = 2805

As Amount = Principal +Interest

=8500 +2805

Amount      =11305.

##### Question-12: A sum of money put at 9% per annum simple interest amounts to ₹10160 in 3 years. What will it amount to in 2 years at 8% per annum?

Solution:  Find the interest percentage earned in 3 years:

1 year = 9%

3 years = 9 x 3 = 27%

Find the principal amount:

Interest = 27%

Percentage of money with interest = 100 + 27 = 127%

Sum of money with interest = Rs 10160

127% = rs 10160

1% = 10160 ÷ 127 = Rs 80

100 = Rs 80 x 100 = Rs 8000

Find the interest for 2 years at 8% per annum:

1 year = 8% x 8000 = 0.08 x 8000 = Rs 640

2 years = 640 x 2 = Rs 1280

Find the amount after 2 years:

Total amount = Rs 1280 + Rs8000 = Rs 9280.

— : End of Simple Interest Class 7 RS Aggarwal Exe-11A Goyal Brothers ICSE Foundation Maths Solutions :–