Percentage - Aptitude MCQ Questions and Solutions with Explanations

Required percentage :
$$\eqalign{ & = \left( {\frac{{1987.50}}{{2650}} \times 100} \right)\% \cr & = \left( {\frac{{19875}}{{265}} \times \frac{1}{{100}} \times 100} \right)\% \cr & = 75\% \cr} $$

$$\eqalign{ & \Rightarrow 250{\left( {1 + \frac{R}{{100}}} \right)^3} = 2000 \cr & \Rightarrow {\left( {1 + \frac{R}{{100}}} \right)^3} = \frac{{2000}}{{250}} \cr & \Rightarrow {\left( {1 + \frac{R}{{100}}} \right)^3} = 8 = {\left( 2 \right)^3} \cr & \Rightarrow \left( {1 + \frac{R}{{100}}} \right) = 2 \cr & \Rightarrow \frac{R}{{100}} = 1 \cr & \Rightarrow R = 100 \% \cr} $$

(7.9% of 134) - (3.4% of 79)
$$ = \left( {\frac{{79}}{{10}} \times \frac{1}{{100}} \times 134} \right) - $$     $$\left( {\frac{{34}}{{10}} \times \frac{1}{{100}} \times 79} \right)$$
$$\eqalign{ & = \frac{{79}}{{1000}} \times \left( {134 - 34} \right) \cr & = \frac{{79}}{{1000}} \times 100 \cr & = \frac{{79}}{{10}} \cr & = 7.9 \cr} $$

Let 36% of 365 + x% of 56.2 = 156.69
Then,
$$ \Rightarrow \left( {\frac{{36}}{{100}} \times 365} \right) + \left( {\frac{x}{{100}} \times 56.2} \right)$$       $$ = 156.69$$
$$\eqalign{ & \Rightarrow \frac{{281}}{{500}}x = 156.69 - 131.4 \cr & \Rightarrow \frac{{281}}{{500}}x = 25.29 \cr & \Rightarrow x = \frac{{25.29 \times 500}}{{281}} \cr & \Rightarrow x = 45 \cr} $$

Let Reena's yearly income be Rs. x
Anubhab monthly income
= Rs. $$\frac{240000}{12}$$
= Rs. 20000
Then,
⇒ 25% of x = 75% of 20000
⇒ $$\frac{25}{100}$$x = $$\frac{75}{100}$$ × 20000
⇒ $$\frac{x}{4}$$ = 15000
⇒ x = 60000
∴ Reena's monthly income :
= Rs. $$\frac{60000}{12}$$
= Rs. 5000

= 140% of 56 + 56% of 140
$$\eqalign{ & = \left( {\frac{{140}}{{100}} \times 56} \right) + \left( {\frac{{56}}{{100}} \times 140} \right) \cr & = 78.4 + 78.4 \cr & = 156.8 \cr} $$

Number of rolls sold by noon = $$\frac{1}{2}$$ of 40 dozen = 20 dozen
Number of rolls sold between noon and closing time :
= 60% of 20 dozen
= $$\left( {\frac{{60}}{{100}} \times 20} \right)$$   dozen
= 12 dozen
Number of rolls left unsold :
= [40 - (20 + 12)] dozen
= 8 dozen

Let 35568 ÷ x% of 650 = 456
Then,
$$\eqalign{ & \Rightarrow 35568 \div \left( {\frac{x}{{100}} \times 650} \right) = 456 \cr & \Rightarrow \frac{{13x}}{2} \times 456 = 35568 \cr & \Rightarrow 2964x = 35568 \cr & \Rightarrow x = \frac{{35568}}{{2964}} \cr & \Rightarrow x = 12 \cr} $$

$$\eqalign{ & \frac{5}{6} = \left( {\frac{5}{6} \times 100} \right)\% \cr & \,\,\,\,\,\, = 83\frac{1}{3}\% \cr & \frac{2}{3} = \left( {\frac{2}{3} \times 100} \right)\% \cr & \,\,\,\,\,\, = 66\frac{2}{3}\% \cr & \frac{2}{5} = \left( {\frac{2}{5} \times 100} \right)\% \cr & \,\,\,\,\,\, = 40\% \cr & \frac{1}{4} = \left( {\frac{1}{4} \times 100} \right)\% \cr & \,\,\,\,\,\, = 25\% \cr & \frac{2}{{11}} = \left( {\frac{2}{{11}} \times 100} \right)\% \cr & \,\,\,\,\,\,\,\,\, = 18\frac{2}{{11}}\% < 20\% \cr} $$

Sonal's annual salary = Rs. 108000
∴ Sonal's monthly salary
= Rs. $$\left( {\frac{{108000}}{{12}}} \right)$$
= Rs. 9000
Nandini's monthely salary
= Rs. (9000 × 2)
= Rs. 18000
Let Kaushal's monthly salary be Rs. x
Then,
12% of x = 16% of 18000
⇒ $$\frac{{12}}{{100}}$$x = $$\left( {\frac{{16}}{{100}} \times 18000} \right)$$
⇒ $$\frac{{12}}{{100}}$$x = 2880
⇒ x = $$\left( {\frac{{2880 × 100}}{{12}}} \right)$$
⇒ x = 24000