1. x * 12 = 75% of 336 Find x.
a) 27
b) 25
c) 21
d) 19
Explanation:
$$\eqalign{ & 12x = \frac{{ {75 \times 336} }}{{100}} \cr & x = \frac{{ {75 \times 336} }}{{ {100 \times 12} }} \cr & x = 21 \cr} $$
2. A shop sells floor tiles at Rs. 48 per square meter. A contractor employs a machine that polishes the tiles that damages 10% of the total number of tiles which cannot be used any more. Calculate the amount that needs to be paid by contractor to tile shop owner, if the hall is of a square shape and has a perimeter of 400 meters?
a) Rs. 4,00,000
b) Rs. 5,00,000
c) Rs. 5,28,000
d) Rs. 3,65,000
Explanation: Let the side of the square shaped hall be X meter
Perimeter = 4X
4X = 400
X = 100m
Area of the hall = 100 × 100 = 10000 sq. meter.
The cost on total tiles = 10000 × 48 = Rs. 480000
But, 10% damage has occurred on tiles which will also be included in cost i.e
Total cost = 480000 + 10% of 480000 = 480000 + 48000
Total cost = Rs. 5,28,000
3. 125% of 860 + 75% of 480 = ?
a) 1415
b) 1385
c) 1435
d) None of these
Explanation:
$$\eqalign{ & { {\frac{{ {125 \times 860} }}{{100}}} + {\frac{{75 \times 480}}{{100}}} } \cr & = 1075 + 360 \cr & = 1435 \cr} $$
4. A person subscribing to sky cable for a year pack Rs. 1785. If the monthly subscription is Rs. 175, how much discount does a yearly subscriber get?
a) 11%
b) 13%
c) 15%
d) 18%
Explanation: Yearly subscription rate = Rs. 1785
Charge for 12 month as rate Rs. 175 per month
= 12 × 175 = Rs. 2100
Discount = 2100 - 1785 = Rs. 315
% discount = $$\frac{{315 \times 100}}{{2100}}$$ = 15%
5. In a metro train there are 600 passengers out of which 34% are females. Fare of each male is Rs. 20 and each female's fare is 25% less than each male. What is the total revenue generated by all the passengers together?
a) Rs. 10880
b) Rs. 10980
c) Rs. 10740
d) Rs. 10680
Explanation: Total Passengers = 600
No. of females = $$\frac{{600 \times 34}}{{100}}$$ = 204
No. of male passengers
= 600 - 204 = 396
Fare of each male = Rs. 20
Fare of female, 15% less,
= $$\frac{{20 \times 75}}{{100}}$$ = Rs. 15 each
Total revenue generated by male
= 396 × 20
= Rs. 7920
Total revenue generated by female
= 204 × 15
= 3060
Total Revenue
= 7920 + 3060
= Rs. 10980
6. In a competitive examination in State A, 6% candidates got selected from the total appeared candidates. State B had an equal number of candidates appeared and 7% candidates got selected with 80 more candidates got selected than A. What was the number of candidates appeared from each State ?
a) 7600
b) 8000
c) 8400
d) 8800
Explanation: Let the number of candidates appearing from each state be X.
7% of X - 6% of X = 80
1% of X = 80
X = 80 × 100
X = 8000
7. Three candidates contested an election and received 1136, 7636 and 11628 votes respectively. What percentage of the total votes did the winning candidate get ?
a) 45 %
b) 57 %
c) 60 %
d) 65 %
Explanation:
$$\eqalign{ & {\text{Total number all three got together is}} \cr & = {1136 + 7636 + 11628} \cr & = 20400 \cr & \% {\text{ of vote the winning candidate got is}} \cr & = {\frac{{11628}}{{20400}}} \times 100 \cr & = 57\% \cr} $$
8. Fresh grapes contain 80% while dry grapes contain 10% water. If the weight of dry grapes is 250 kg, what was its total weight when it was fresh?
a) 1000 kg
b) 1125 kg
c) 1225 kg
d) 1100 kg
Explanation: Quantity of water in 250 kg dry grapes,
$$ = \frac{{10}}{{100}} \times 250 = 25\,{\text{kg}}$$
Pulp of grapes = 225 kg
We get 20 kg pulp in 100 kg fresh grapes.
To get 225 kg pulp, we need fresh grapes,
$${\text{ = }}\frac{{100 \times 225}}{{20}} = 1125\,{\text{kg}}$$
9. A population of variety of tiny bush in an experiment field increased by 10% in the first year, increased by 8% in the second year but decreased by 10% in third year. If the present number of bushes in the experiment field is 26730, then the number of variety of bushes in beginning was:
a) 35000
b) 27000
c) 25000
d) 36000
Explanation: Let the number of bushes originally be 100
Number of bushes after one year
100 ==10% (↑) ==> 110
After second year it becomes
110 ==8%(↑) ==> 118.8
After third year,
118.8 ==8%(↓)==> 109.3
Now,
109.3 = 26730
1 = $$\frac{{26730}}{{109.3}}$$
So, 100 = $$\frac{{26730}}{{109.3}} \times 100$$ = 25000
Number of bushes originally was 25000
10. If a% of x is equal to b% of y, then of c% of y is what % of x ?
a) c %
b) $$\frac{{{\text{ac}}}}{{\text{b}}}$$ %
c) $$\frac{{{\text{bc}}}}{{\text{a}}}$$ %
d) abc %
Explanation:
$$\eqalign{ & \frac{{ {ax} }}{{100}} = \frac{{ {by} }}{{100}} \cr & ax = by \cr & y = \frac{{ {ax} }}{b} \cr & c\% \,{\text{of}}\,y = \frac{{ {cy} }}{{100}} \cr & \frac{{ {cy} }}{{100}} = \frac{{ {cax} }}{{100b}} \cr & c\% \,{\text{of}}\,y = \frac{{ca}}{b}\% \,{\text{of}}\,x \cr} $$