SCERT AP 7th Class Maths Solutions Pdf Chapter 7 Ratio and Proportion Ex 7.7 Textbook Exercise Questions and Answers.

## AP State Syllabus 7th Class Maths Solutions 7th Lesson Ratio and Proportion Ex 7.7

Question 1.

Calculate the simple interest accrued on a sum oR 12600, at the rate of 9% per annum for 2 years.

Answer:

Given principle = ₹ 12600

Time = 2 years

Rate of Interest = 9%

∴ Simple Interest = ₹ 2268

Question 2.

Calculate the simple interest accrued for 3 years and the total amount on a sum of ₹ 85000, at the rate of 11% per annum.

Answer:

Given Principle = ₹ 85000

Time = 3 years

Rate of Interest = 11%

Simple Interest = ₹ 28,050

Total amount = Principle + Interest

= 85000 + 28050

∴ Total amount = ₹ 1,13,050

Question 3.

In what time will ₹ 45000 amounts to ₹ 63000, If the simple Interest Is calculated 10% per annum?

Answer:

Method 1:

Given principle = ₹ 45000

Rate of Interest = 10%

Amount = ₹ 63000

Let the time = x years

Interest = ₹ 4500 x

Amount = Principle + Interest

= 45000 + 4500x = 63000

= 4500x = 63000 – 45000 = 18000

⇒ x = \(\frac{18000}{4500}\) = 4

∴ Time = 4 years

Method 2:

Given A = ₹ 63000;

P = ₹ 45000; R = 10%; T=?

So I = A – P = 63000 – 45000 = ₹ 18000

But I = \(\frac{\text { PTR }}{100}\)

⇒ 18000 = \(\frac{45000 \times T \times 10}{100}\)

∴ T = \(\frac{18000 \times 100}{45000 \times 10}\) = 4 years

Question 4.

On a certain amount at the rate of 12% per annum for time 3 years the toti1 interest becomes ₹ 18000. What is the principal amount?

Answer:

Given Rate of Interest = 12%

Time.= 3 years

Interest = ₹ 18000

Let Principle = ₹ x

∴ Principle = ₹ 50,000

Question 5.

In what time the simple interest accrued on a sum of?35000 at the rate of 13% per annum becomes?27300?

Answer:

Given Principle = ₹ 35000 ;

Rate of Interest = 13% ;

Time = x years

Interest = ₹ 27300 .

Time = 6 years