# ML Aggarwal CBSE Solutions Class 8 Math Seventh Chapter Compound Interest Exercise 7.1

## ML Aggarwal CBSE Solutions Class 8 Math 7th Chapter Compound Interest Exercise 7.1

(1) A = P (1+ R/100)n

Given P = 6000/-

R = 10%

N = 2 years

= 6000 (1+ 10/100)2

= 6000 X (100+10/100)2

= 6000 X (110/100)2

= 6000 X 110/100 X 110/100

= 7260

∴ C.I. = A – P = 7260 – 6000

= 1260 /- (Ans)

(4) (i) P1 for 1 year = 46875 /-

R = 4%

T1 = 1 year

I for 1 year = P1RT1/100

= 46875 X 4 X 1/100

= 1875 /- (Ans)

(ii) P2 for 2 year = 46875 + 1875

= 48750 /-

R = 4 %

T1 = 2 years

I for 2nd year = P2 R T2/100

= 48750 X 4 X 1/100

= 1950

Amount after 2nd year = 48750 + 1950

= 50700

(iii) P3 for 3rd year = 50700 /-

R = 4%

T3 = 3 years

I for 3 years = P3 R T3/100

= 50700 X 4 X 1/100 = 2028 /- (Ans)

(5) For 1st year =>

P1 = 6000, R = 10% T1 = 1

∴ I, P1 R T1/100

= 6000 X 10 X 1/100 = 600/-

∴ A1 at the end of 1st year = 6000 + 600

= 6600 /-

For 2nd year à

P2 = 6600, R = 10%, T2 = 1

∴ I2 = P2R T2/100 = 6600 X 10 X 1/100

= 660/- (Ans)

A2 at the end of 2nd year = 6600 + 660

= 7260/-

For, 3rd year ->

P3 = 7260, R = 10% , T2 = 1

∴ I3 = P3 R T3 /100

= 7260 X 10 X 1/100

= 726

∴ A3 at the end of 3rd year = (7260+726)

= 7986 /- (Ans)

(6) For 1 year

P1 = 5000 /-

R1 = 6%

T1 = 1

∴ I2 = P1 R1 T1/100 = 5000 X 6 X 1/100

= 300 /-

End of 1 year the amount will be =>

∴ A1 = 5000 + 300 = 5300 /-

For 2nd year =

P2 = 5300 /-

R2 = 8%

T2 = 1 year

∴ I2 = P2 R2 T2/100 = 5300 X 8 X 1/100

= 424 /-

End of 2 year the amount will be ->

∴ A2 = 5300 + 424

= 5724 /- (Ans)

∴ C.I = 5724 – 5000 = 724/- (Ans)

(7) For, simple interest ->

P = 20000/-, T = 2 years, R = 8%

∴ I = PRT/100 = 20000 X 2 X 8/100 = 3200/-

For compound interest ->

For 1 year –

P1 = 2000/-, R = 8%, T = 1 year

∴ I = PRT/100 = 20000 X 8 X 1/100 = 1600/-

∴ A1 after 1 year = 20000 + 1600 = 21600/-

For, 2nd years –

P2 = 21600/- R = 8% T = 1 year

∴ I = PRT/100

= 26100 X 8 X 1/100

= 2088/-

A2 at after 2nd year = 26100 + 2088

= 28188/-

∴ C.I. = 28188 – 20000 = 8188/-

∴ Difference between C.I & S.I

= 8188 – 3200 = 4988/- (Ans)

Updated: May 29, 2021 — 5:30 pm