Percentage - Aptitude MCQ Questions and Solutions with Explanations

Answer: Option A

Weight of metal A = 5kg
Total weight of the alloy :
= (5 + 20) kg
= 25 kg
∴ Required percentage :
$$\eqalign{ & = \left( {\frac{5}{{25}} \times 100} \right)\% \cr & = 20\% \cr} $$

Answer: Option C

Let 23% of 8040 + 42% of 545 = x% of 3000
Then,
$$\left( {\frac{{23}}{{100}} \times 8040} \right) + \left( {\frac{{42}}{{100}} \times 545} \right)$$       = $$\left( {\frac{x}{{100}} \times 3000} \right)$$
$$\eqalign{ & \Rightarrow 30x = 1849.2 + 228.9 \cr & \Rightarrow 30x = 2078.1 \cr & \Rightarrow x = \frac{{2078.1}}{{30}} \cr & \Rightarrow x = 69.27 \cr} $$

Answer: Option C

Total sales tax paid = 7% of Rs. 400 + 9% of Rs. 6400
= Rs. $$\left( {\frac{7}{{100}} \times 400 + \frac{9}{{100}} \times 6400} \right)$$
= Rs. (28 + 576)
= Rs. 604
Total cost o the items :
= Rs. (400 + 6400)
= Rs. 6800
∴ Required percentage
$$\eqalign{ & = \left( {\frac{{604}}{{6800}} \times 100} \right)\% \cr & = 8\frac{{15}}{{17}}\% \cr} $$

Answer: Option D

Let the number be = $$x$$
Then,
⇒ 54% of $$x$$ - 26% of $$x$$ = 22526
⇒ $$\frac{{54}}{{100}}$$ $$x$$ - $$\frac{{26}}{{100}}$$ $$x$$ = 22526
⇒ $$\frac{{28}}{{100}}$$ $$x$$ = 22526
⇒ $$x$$ = $$\left( {\frac{{22526 × 100}}{28}} \right)$$
⇒ $$x$$ = 80450
∴ 66% of 80450 = $$\left( {\frac{{66}}{{100}} \times 80450} \right)$$
                          = 53097

Answer: Option C

Let the number be x
Then,
75% of x + 75 = x
⇔ x - $${\frac{{75}}{100}}$$ x = 75
⇔ x - $${\frac{{3}}{4}}$$ x = 75
⇔ $${\frac{{x}}{4}}$$ = 75
⇔ x = 300