Quantitative Aptitude For Competitive Examinations (English) 7th Edition

81.what is the ratio of the surface area formed by placing 3 cubes adjacently to the sum of the individual surface area of these 3 cubes?

A.7:9 B.27:23 C.49:81 D.9:7

ANS: Volume of a cube = 6a

^{2}
Volume of 3 cubes = 18a

^{2}
Volume of three cubes placing adjacent each other = 6a

^{2}+5a^{2}+5a^{2}= 16a^{2}
Ratio= 16/18 = 8:9

82.At what rate percent CI does a sum of money become nine fold in 2 years?

a.100% p.a b.300% p.a c.400% p.a d.200% p.a

Ans: . P(1+(r/100))

^{2 }= 9P
r=200%

84.the SI on a sum of Rs.12,000 at a rate of 15% p.a is Rs.5,400.determine the time for which the sum is borrowed,

a.2 years b.3 years c.1.5 years d.2.5 years

Solution: SI=PTR/100

5400=(1200*15*T)/100

T=3

85.In a single throw of a fair dice,what is the probability that the no appearing on the top face of the dice is more than than 2?

a.1/3 b.3/4 c.2/3 d.1/2

Ans: here,probability more than that the no is more than 2 is 4.

so, we know that the formula..p(x)=no.of favourable cases/no. of outcomes

so,it is 4/6=2/3 option C.

86.if x=12 , y=4, then find the values of (x+y)

^{x/y}
a. 8009 b.4096 c.none d.1024

Ans:Here,12+4 is 16 and it is written as 2 power4 ,then 12/4 is 3,so now it is 2 power 12 so ans is 4096.

87.The salary of ramu is 3 times the salary of raju's salary increases by 20% every month &ramu's salary decreases by 10% every month,what is the ratio of salary of raju to ramu after 2 months?

a.15:24 b.17:28 c.14:23 d.16:27

Ans: let salary of raju is P

Then ramu’s salary is 3P

After 2 months raju’s salary becomes P(1+20/100)

^{2}-- (1)
After 2 months ramu’s salary becomes 3P(1+20/100)

^{2 }--(2)
Ratio= (1)/(2) = 16:27

88.There are 2 vessels which are filled with milk of 2 qualities worth Rs.10 per litre and Rs.11 per litre.In what approximation ratio these two be mixed to get a new quality of milk of worth Rs.10.67 per litre?

a.12:3 b.1:3 c.1:2 d.2:1

ans:1:2

(10*1+11*2)/1+2=10.66666(approx 10.67) by option verification.

89. A sum of Rs.5000 was divided among P, Q and R in the ratio of 2:3:5. If the amount of Rs 500 was added to each, what will be their new ratio?

Options: a) 3:4:6 b) 3:5:4 c) 3:4:5 d) 2:3:4

Divide 5000 in the ratio of 2:3:5 then 1000, 1500, 2500

Add 500 to 1000, 1500 and 2500 then 1500: 2000: 3000

3:4:6

90. There are two vessels which are filled with milk of two qualities worth Rs10 per liter and Rs 11 per liter. In what approximate ratio, these two be mixed to get a new quality of milk of worth Rs 10.67 per liter?

Options: a) 1:3 b) 1:2 c) 2:3 d) 2:1

Ans: 10 * x + 11 * y = (x+y) * 10.67 ( Assume x & y quantity in vessels 1 & 2 respectively )

Solve for x/y = 1:2

91. The retail price of a toothpaste of 140 grams is Rs 40, the shopkeeper gives a toothbrush whose actual price is Rs 10, free with it and still gains 25% . The cost price of the toothpaste is :

Options: a) Rs.36 b) Rs.24 c) Rs. 30 d) none of the mentioned options.

Ans: Selling price = 40 – 10 = 30 Rupees.

Let cost price =x;

Selling price = cost price + profit on cost price

30 = x + 25% of x;

X= 24

92. The section of a solid right circular cone by a plane containing vertex and perpendicular to base is an equilateral triangle of side 10 cm. Find the volume of the cone?

Options: a) 226.61 cm^3 b) 223.73cm^3 c) 228.73cm^3

Answer is 326.61 cm

^{3}
93. 5 boys and 5 girls were made to sit around a round table alternatively. How many of such arrangements are possible?

Options: a) 14400 b) 7200 c) 28800 d) 1152

Ans: In general, the number of ways of arranging n objects around a round table is (n-1)!

Arranging girls is 4! Then arranging boys is 5! So total is 2880

94. Determine the speed of a train of length 240 meters if it crosses a pole in 15 seconds.

Options: a) 44.4 kmph b) 57.6 kmph c) 33.3 kmph d) 22.2 kmph

speed = distance/ time

Ans: 57.6

95. For p= 5 and q= -5, the value of (9p^2+36pq+36q^2) is:

Options: a) 900 b) 15 c) 30 d) 225

Ans: (3p + 6q)

^{2 }
Ans: 225

96. For all integral values of n, the expression ((7^2n)-(3^3n)) is a multiple of:

Options: a) 10 b) 31 c) 12 d)22

Ans: take n=1 then verify options

Ans: 10

97. A sum of money at CI amounts to thrice itself in three years. In how many years will it be 9 times itself?

Options: a) 6years b) 2 years c)5 years d) 3 years

Ans: P(1+r/100)

^{3}= 3P
So (1+r/100)

^{3}=3
To become 9 times squaring on both sides

(1+r/100)

^{6}= 9
So 6 years

98. A 3 digit number is formed with the digits 1,3,6,4 and 5 at random with no digits being repeated in the same number. What is the chance that the number formed is divisible by 2?

Options: a) 4/5 b)3/5 c)2/5 d)1/5

Ans: Total cases = 5*4 * 3 = 60

_ _ _

3

^{rd}digit should be filled either by 6 or 4 so two ways
First place is filled with 4 ways as we have used one digit in 3

^{rd}place
Second digit is filled with 3 ways.

So favourable cases = 2 * 4 * 3= 24

Probability = 24/60

TOTAL SALES IN 2013 = Rs. 500 lakhs

TOTAL SALES IN 2014 =Rs. 600 lakhs.

100. What is the difference in revenue earned by stumps in two years?

Options: a) 16 lakhs b) 10 lakhs c) 14 lakhs d) 12 lakhs

Ans: 14 lakhs

101. The revenue earned by pads in the year 2013 is what percent of the revenue earned by gloves in the year 2014? Options: a) 83.3% b) 58.5% c) 43.3% d) 72.5%

Ans: 83.3%

102. What is difference between the revenue earned by pads in 2014 and revenue earned by balls in 2013?

Ans: 7 lakhs