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**Simple Interest – Maharashtra Board Class 6 Solutions for Mathematics (English Medium)**

MathematicsGeneral ScienceMaharashtra Board Solutions

### Exercise-69

**Solution 1:**

- Principal = Rs. 25000

Interest = Rs. (32500 – 25000) = Rs. 7500

Period = 3 years. - Principal = Rs. 8000

Interest = Rs. (8480 – 8000) = Rs. 480 Period = 6 months. - Principal = Rs. 6,00,000

Interest = Rs. (840000 – 600000) = Rs. 2,40,000

Period = 5 years.

### Exercise-70

**Solution 1:**

- If a person borrows Rs. 100 from the Jijamata Co-operative Credit Society for one year, he must pay an interest of Rs. 12 to the Society at the end of the year.
- If you borrow Rs. 100 from the Rajgad Sahakari Bank for one year, you must pay the bank Rs. 8 as interest at the end of the year.
- If Sarjerao takes a loan of Rs. 100 for one year from the Zilla Central Bank, he must pay Rs. 10 to the bank as interest for the year.

### Exercise-71

**Solution 1:**

- Rate of interest = 8 p.c.p.a.

This means the interest on Rs. 100 for 1 year is Rs. 8.

∴ The interest on Rs. 100 for 5 years will be 8 × 5 = Rs. 40. - Rate of interest = 12 p.c.p.a.

This means the interest on Rs. 100 for 1 year is Rs. 12.

∴ The interest on Rs. 100 for 3 years will be 12 × 3 = Rs. 36. - Rate of interest = 5 p.c.p.a.

This means the interest on Rs. 100 for 1 year is Rs. 5.

∴ The interest on Rs. 100 for 20 years will be 5 × 20 = Rs. 100. - Rate of interest = 9 p.c.p.a.

This means the interest on Rs. 100 for 1 year is Rs. 9.

∴ The interest on Rs. 100 for 4 years will be 9 × 4 = Rs. 36. - Rate of interest = 7 p.c.p.a.

This means the interest on Rs. 100 for 1 year is Rs. 7.

∴ The interest on the same principal for 2 years will be 7 × 2 = Rs. 14. - Rate of interest = 4 p.c.p.a.

This means the interest on Rs. 100 for 1 year is Rs. 4.

∴ The interest on the same principal for 7 years will be 4 × 7 = Rs. 28.

**Solution 2(1):**

The principal remains the same but the period increases 5 times.

∴ The interest will also increase fivefold.

∴ Interest for 5 years = 720 × 5 = Rs. 3,600.

**Solution 2(2):**

The principal remains the same but the period increases 3 times. (2 years × 3 years = 6 years)

∴ The interest will also triple.

∴ Interest for 6 years = 3300 × 3 = Rs. 9,900.

### Exercise-72

**Solution 1:**

- Rate of interest = 10 p.c.p.a

A year’s interest on Rs. 100 is Rs. 10.

Principal is Rs. 6000 i.e. 60 times Rs. 100.

Period is the same.

∴ Interest = 60 times Rs 10.

∴ Interest = 10 × 60 = Rs. 600 - Rate of interest = 14 p.c.p.a

A year’s interest on Rs. 100 is Rs. 14.

Principal is Rs. 500 i.e. 5 times Rs. 100.

Period is the same.

∴ Interest = 5 times Rs. 14.

∴ Interest = 14 × 5 = Rs. 70. - Rate of interest = 9 p.c.p.a

A year’s interest on Rs. 100 is Rs. 9.

Principal is Rs. 15,000 i.e. 150 times Rs. 100.

Period is the same.

∴ Interest = 150 times Rs. 9.

∴ Interest = 9 × 150 = Rs. 1350. - Rate of interest = 6 p.c.p.a

A year’s interest on Rs. 100 is Rs. 6.

Principal is Rs. 12000 i.e. 120 times Rs. 100.

Period is the same.

∴ Interest = 120 times Rs. 6.

∴ Interest = 6 × 120 = Rs. 720 - Rate of interest = 3 p.c.p.a

A year’s interest on Rs. 100 is Rs. 3.

Principal is Rs. 25000 i.e. 250 times Rs. 100.

Period is the same.

∴ Interest = 250 times Rs. 3.

∴ Interest = 3 × 250 = Rs. 750. - Rate of interest = 11 p.c.p.a

A year’s interest on Rs. 100 is Rs 11.

Principal is Rs. 8000 i.e. 80 times Rs. 100.

Period is the same.

∴ Interest = 80 times Rs. 11.

∴ Interest = 11 × 80 = Rs. 880.

**Solution 2(1):**

The period and the rate of interest remain the same. The new principal Rs. 15000 is 3 times the old principal Rs. 5000.

∴ Interest also will be 3 times of Rs. 1200∴ Interest on Rs. 15000 = 1200 × 3 = Rs. 3600

**Solution 2(2):**

### Exercise-73

**Solution 1:**

- Rate of interest is 6 p.c.p.a.∴ Interest on a principal of Rs. 100 for 1 year = Rs. 6

∴ Interest on a principal of Rs. 100 for 5 years = 6 × 5 = Rs. 30.

Now, 400 is 4 times Rs. 100.∴ Interest on Rs. 400 for 5 years = Rs. 30 × 4 = Rs. 120. - Rate of interest is 4 p.c.p.a.∴ Interest on a principal of Rs. 100 for 1 year = Rs. 4

∴ Interest on a principal of Rs. 100 for 3 years = 4 × 3 = Rs. 12.

Now, 1500 is 150 times Rs. 100.∴ Interest on Rs. 1500 for 3 years = Rs. 12 × 15 = Rs. 180. - Rate of interest is 8 p.c.p.a.∴ Interest on a principal of Rs. 100 for 1 year = Rs. 8

∴ Interest on a principal of Rs. 100 for 4 years = 8 × 4 = Rs. 32.

Now, 15000 is 150 times Rs. 100.∴ Interest on Rs. 15000 for 4 years = Rs. 32 × 150 = Rs. 4800. - Rate of interest is 10 p.c.p.a.∴ Interest on a principal of Rs. 100 for 1 year = Rs. 10

∴ Interest on a principal of Rs. 100 for 2 years = 10 × 2 = Rs. 20.

Now, 20000 is 200 times Rs. 100.∴ Interest on Rs. 20000 for 2 years = Rs. 20 × 200 = Rs. 4000. - Rate of interest is 5 p.c.p.a.∴ Interest on a principal of Rs. 100 for 1 year = Rs. 5

∴ Interest on a principal of Rs. 100 for 6 years = 5 × 6 = Rs. 30.

Now, 3500 is 35 times Rs. 100.∴ Interest on Rs. 3500 for 6 years = Rs. 30 × 35 = Rs. 1050.