**Collins Maths Solutions Class 7 Chapter 9 Simple Interest**

Welcome to NCTB Solution. Here with this post we are going to help 7th class students for the Solutions of Collins Maths Class 7 Mathematics, Chapter 9, Simple Interest. Here students can easily find chapter 7 solutions with exercise wise explanation. Students will find proper solutions for Exercise 9.1 Our teacher’s solved every problem with easily understandable methods so that every students can understand easily. Here in this post all the solutions are based on ICSE latest Syllabus.

**Simple Interest Exercise 9.1 Solution :**

**Question no – (1)**

**Solution : **

**(a) Principal = Rs 480**

Rate of interest = 5 1/4%

Time = 1 1/4 years

**∴** Simple interest,

= 480 × 21 × 5/4 × 4 × 100

= 31.5 Rs

Thus, the simple interest will be 31.5 Rs.

**(b) Principal = Rs 2224**

Rate of interest = 6.25%

Time = 2 years 3 month = (12 + 3) m = 15 month.

**∴** Simple interest,

= (2224 × 6.25/100 × 2 × 3/12)

= (278 + 354.75

= 312.75 Rs.

Hence, the simple interest will be Rs 312.75

**Question no – (2) **

**Solution : **

**(a) Interest = Rs 455**

Rate of interest = 2 1/3%

Time = 3 years

**∴** Simple interest,

= P × 7/3 × 3/100

= 455 = 21P/300

= 21P = 455 × 300

= P = 455 × 300/21

= P = 6500 Rs.

So, the amount of borrowed sum will be 6500 Rs.

**(b) Interest = Rs 675,**

Rate if interest = 12 %

Time = 36 month

**∴** Simple interest = P × 12 × 3/100

= 675 = P × 36/100

= P = 100 × 675/36

= 1875 Rs.

Therefore, the amount of borrowed sum will be 1875 Rs.

**Question no – (3) **

**Solution : **

**(a) Principal = RS 1000**

Interest = Rs 210

Time = 3 1/2 year.

**∴** Simple interest = 1000 × R × 7/2 × 100

= 210 = 1000 × 7R/2 × 100

= R = 2 × 100 × 210/1000 × 7

= R = 6%

Therefore, rate of interest will be 6%.

**(b) Principal = Rs 30,000**

Interest = Rs 2310

Time = 2.2 years

**∴** Simple interest,

= 2310 = 30,000 × R × 2.2/100

= R = 2310 × 100/30,000 × 2.2

= 3.5%

Hence, the rate of interest will be 3.5%.

**Question no – (4)**

**Solution : **

**(a) Principal = Rs 1800**

Rate = 10% p.a.,

Interest = Rs 420

**∴**** **420 = 1800 × 10 × t/100

= 1800 × 10 × t = 420 × 100

= t = 420 × 100/1800 × 10

= 2.33

= 2 1/3 years.

So, the required time period will be 2 1/3 years.

**(b) Principal = 1080**

Rate = 3 1/3% p.a.,

Interest = Rs 90

**∴**** **90 = 1080 × 10 × t/3 × 100

= t = 3 × 100 × 90/1080 × 10

= 2.5 years.

Thus, the required time period will be 2.5 years.

**Question no – (5)**

**Solution : **

Amount = P (1 + RT/100)

= 92400 = P (1 + 15 × 2/100)

= P (1 + 30/100)

= P × 13/10

= P = 92400 × 10/13

= P = 71, 077 Rs

Therefore, the borrowed sum will be 71,077 Rs.

**Next Chapter Solution : **

👉 Chapter 10 👈