Question

Find the interest and the amount on :
(i) 750 in 3 years 4 months at 10% per
annum.
(ii) * 5,000 at 8% per year from 23rd
December 2011 to 29th July 2012.
(iii) 2,600 in 2 years 3 months at 1% per
month.
1
(iv) 4,000 in 1
3
years at 2 paise per rupee
per month
3 2​

Answer 1

Step-by-step explanation:

(I) Given P = ₹750

Time (T) = 3. 4/12 = 3.1/3

= 10/3 years

Rate (R) = 10%

∴ Interest (I) = PRT/100 = (750 × 10 × (10/3))/100

= (250 × 10 × 10)/100 = ₹250

∴ Amount (A) = P + I = ₹750 + ₹250 = ₹1000

(ii) Principal (p) = ₹5000

Rate (R) = 8% p.a

Time (T) = 23 December 2011 to 29 July 2012

Dec. Jan. Feb. March April May June July

8 31 29 31 30 31 30 29

Total 219 days = (219/365) Years

∴ Interest = PRT/100 = (5000 × 8 × 219)/(100 × 365)

= 10 × 8 × 3 = ₹240

(iii) Here P = ₹2,600

Time (T) = 2 years 3 months = 27 months

Rate (R) = 1 % per month

∴ Interest = (P × T × R) /100 = (2600 × 27 × 1)/100

= 26 × 27 = Rs. 702

∴ Amount = Rs. (2600 + 702) = Rs. 3302

(iv) Here P = Rs. 4,000, Time (T) 1. 1/3 year

= 1 year + (12/3) months = 16 months

Rate (R) = 2 paise per rupee per month = 2% per month

∴ Interest (I) = (P × T × R)/100 = (4000 × 2 × 16)/100

= 40 × 32 = Rs. 1280

∴ Amount (A) = P + I = Rs. 4000 + Rs. 1280

= Rs. 5280