Tine borrowed $70 000 on a bank, a/mt. charged interest at rate of 13/2 per annum for 2 years. a) Calculate the interest paid for the 1st year. b) How much money in total did she pay back at the end of the two years?

Fomula ya riba rahisi ($I$) ni:

$$I = \frac{P \times R \times T}{100}$$

Kwa mwaka wa kwanza, $T = 1$ mwaka.

$$I = \frac{840,000}{100}$$ $$I = 8,400$$

Riba aliyolipa kwa mwaka wa kwanza ni:

$$\boxed{\text{Sh 8,400}}$$

Kwa riba rahisi, riba kwa kila mwaka ni sawa. Kwa hivyo, riba kwa miaka miwili ni:

$$I_{jumla} = \text{Riba kwa mwaka wa kwanza} \times 2$$ $$I_{jumla} = 8,400 \times 2 = 16,800$$

Au, kwa kutumia fomula ya riba rahisi na $T=2$:

$$I_{jumla} = \frac{70,000 \times 12 \times 2}{100}$$ $$I_{jumla} = \frac{1,680,000}{100}$$ $$I_{jumla} = 16,800$$

Jumla ya kiasi ($A$) alicholipa ni jumla ya kiasi cha mkopo na riba yote:

$$A = P + I_{jumla}$$

$$A = 70,000 + 16,800$$ $$A = 86,800$$

Jumla ya kiasi alicholipa mwishoni mwa miaka miwili ni:

$$\boxed{\text{Sh 86,800}}$$