Question

Fill in the blanks in the table.

	Principal	Rate of interest (p.c.p.a)	Time	Interest	Amount
i.	Rs. 4200	7%	3 years
ii.		6%	4 years	Rs.1200
iii.	Rs.8000	5%		Rs. 800
iv.		5%		Rs.6000	Rs. 18000
v.		2(1/2)% 2	5 years	Rs. 2400

Answer 1

i. Total interest = (P x R x T)/100

= (4200 x 7 x 3)/100

= Rs. 882

Amount = Principal + interest

= 4200 + 882

= Rs. 5082

ii. Total interest = (P x R x T)/100

∴ 1200 = (P x 6 x 4)/100

∴ (1200 x 100)/(6 x 4) = P

∴ P = Rs. 5000

Amount = Principal + interest 

= 5000 + 1200

= Rs. 6200

iii. Total interest = (P x R x T)/100

∴ 800 = (8000 x 5 x T)/100

∴ (800 x 100)/(8000 x 5) = T

∴ T = 2 years

Amount = Principal + interest

= 8000 + 800

= Rs. 8800

iv.  Amount = Principal + Interset 

∴ 1800 = Principal + 6000 

∴ Principal = Rs. 12000

Total interest = (P x R x T)/100

∴ 6000 = (12000 x 5 x T)/100

∴ (6000 x 100)/(12000 x 5) =T

∴ T = 10 years

v. R = 2(1/2)% = 2.5%

∴ Total interest = (P x R x T)/100

∴ 2400 = (P x 2.5 x 5)/100

∴ 2400 = (P x 25 x 5)/(100 x 10)

∴ (2400 x 10 x 100)/(25 x 5) = P

∴ P = Rs. 19200

Amount = Principal + interest

= 19200 + 2400

= Rs. 21600

.	Principal	Rate of interest (p.c.p.a)	Time	Interest	Amount
i.	Rs. 4200	7%	3 years	Rs. 882	Rs. 5082
ii.	Rs. 5000	6%	4 years	Rs.1200	Rs. 6200
iii.	Rs.8000	5%	2 years	Rs. 800	Rs. 8800
iv.	Rs. 12000	5%	10 years	Rs.6000	Rs. 18000
v.	Rs. 19200	2(1/2)% 2	5 years	Rs. 2400	Rs. 21600