Question

₹ 4000 is lent at 5 % for the first year, 10 % for the second year and 8 % for the third year. Find the amount and compound interest​

Answer 1

Answer:

Part A :

⇒  S.I.=  

100

P×R×T

​  

=  

100

4000×8×2

​  

 

∴   S.I.=Rs.640

⇒  C.I.=P(1+  

100

R

​  

)  

T

−P=8000×(1+  

100

8

​  

)  

2

−8000

⇒  C.I.=8000×  

25

27

​  

×  

25

27

​  

−8000

∴    C.I.=Rs.665.6

⇒  Difference between C.I. and S.I. = Rs.665.6−Rs.640=Rs.25.6

∴    A=25.6

⇒   Part B :

⇒  Here, R=10% and C.I.−S.I.=Rs.180

⇒  S.I.=  

100

P×R×T

​  

=  

100

10×P×1

​  

 

∴    S.I.=  

10

P

​  

 

⇒  C.I.=P(1+  

200

R

​  

)  

2

−P

⇒  C.I.=P×(  

200

210

​  

)  

2

−P

⇒  C.I.=  

400

441P

​  

−P

∴    C.I.=  

400

41P

​  

 

⇒  C.I.−S.I.=  

400

41P

​  

−  

10

P

​  

=  

400

P

​  

 

⇒   Given difference is 180

∴    

400

P

​  

=180

∴   P=Rs.72000

∴  B=72000

 

⇒   10A+B=10×25.6+72000=72256

Step-by-step explanation: