Simple Interest Practice objective type question

Answer: c. Rs. 2400
Solution: Let the amount lent at 8% will be x
Amount lent at 10% will be (4000-x) According to the question:
$\frac{x\times 8}{100}+\frac{\left(4000–x\right)\times 10}{100}=352$
$8x+40000–10x=352 \Rightarrow 2x=4800 \Rightarrow x=2400$

Answer: d. 30%
Solution: The difference of percentage between 10 and 13 is 30%

Answer: d. Rs. 245
Solution: $S.I=\frac{700\times 7\times 5}{100}=245$

Answer: c. Rs. 300
Solution: $S.I=\frac{1250\times 6\times 4}{100}=300$

Answer: b. 45 years
Solution: Let the Principal amount be p
After the interest the principal amount will become 2p
Simple interest= 2p-p = p According the question:
$p=\frac{\mathrm{p}\times \mathrm{r}\times 5}{100}$
r= 20;
At become 10 times the simple interest will be 10p-p = 9p
$9p=\frac{\mathrm{p}\times 20\times \mathrm{t}}{100}$
t= 45