a) Rs. 17000
a) Rs. 72000
b) Rs. 36000
c) Rs. 45000
d) Rs. 35000
e) Rs. 54000
a) Rs. 2500
b) Rs. 2000
c) Rs. 3000
d) Rs. 2800
e) Rs. 4500
Solutions:
1). Five years ago, let Arjun’s age be 3x years. Then, Somu’s age = x
Now, according to the question.
(3x +5 + 6)/( x+5+12) = 7/4
or, (3x+11)/( x+17) =7/4
or, 12x + 44 = 7x + 119
or, 5x = 75
:. x = 15
Somu’s age 3 years ago = 15 + (5 – 3) = 17 years
Answer is: C)
2). Total number of eggs = 24
:. 8 eggs are rotten
:. Remaining eggs = (24 – 8); 16 is not rotten
Now, 2 eggs are randomly selected.
Then n(S) =24C2= 23 x 12
:. n(E)=16C1 ×8C1= 16 × 8
:. P(E)= (16×8)/( 23 ×12) = 32/69
Answer is: D)
3). Ratio of profit
= x × 4 + 2x × 8 : 3x ×4 + (3x/2)× 8 :
5x × 4 + (5x/2) ×8 = 20x: 24x: 40x = 5 : 6 : 10
Answer is: D)
4). We know that increase in volume
=3 × x + (3x2/100) + (x3/1002)
As there is decrease, put the -ve value of x.
:. Percentage decrease in volume
=3 × (-30) + [3 × (-30)2 / 100] + [(-30)3 /1002 ]
= – 90 + 27 – 2.7
= -65.7
Note: If you don’t recall the formula, compound it like.
Step I. -30 – 30 + [(-30)(-30)/100]= -51
Step II.-51 -30+ [(-51)(-30)/100]
= – 81 + 15.3
= -65.7
Answer is: E
5). Circumference of the semicircle = r (π+2)
:. r[(22/7)+2] =180
or, r(36/7)=180
r = 35cm
Now, side of the square = 2×35 × (160/100)
=2 × 35 × 1.60 = 70 × 1.60 = 112 cm
:. Perimeter of the square = 4 × 112
= 448 cm
Answer is: D
6). Let the cost of each Sofa be Rs.x,
Now, according to the question,
2x×(114/100)= [(x ×130)/100] + [(x ×130)/100] – 5504
or, 2.28x = 2.6x – 5504
or, 0.32x = 5504
:. x= [(5504 × 100)/32] = 172 × 100= Rs. 17200
Answer is: E)
7). The ratio of milk to water in Jar X
= 180 : 36 = 5:1
Now, let 6x litres of mixture be taken out from Jar X and put in Jar Y.
Then, milk in Jar Y = 5x
Water in Jar Y= x
So, 5x/(x+6) = 5/2
or, 10x=(5x + 30)
or, 5x=30,
:. x=6
Hence the mixture that was taken out from Jar X = 6x =6 × 6 = 36 litres
Answer is: D)
8). Let Prakash’s monthly salary be 9x and Omana’s 7x.
Then, 1/2 of 20% of 7x +(7/9) of 40% of 9x = 17500
or, 10% of 7x + 40% of 7x = 17500
or, 0.7x + 2.8x = 17500
or, 3.5x = 17500
:. x =Rs. 5000
Hence Prakash’s monthly salary = 9 × 5000
= Rs. 45000
Shortcut Method:
According to the question, 7 + 28 = 17500
:. 90 = (17500/35)×90 =45000
Answer is: C)
9). Required difference
= [P+(P×10×2)/100] × [(12×5)/100] – [(P×10×2)/100]
or, [(100P+ 20P)/100] × (60/100) – (20P/100) = 1300
or, (120P/100) × (3/5) – (20P/100)=1300
or, 6P/5 × 3/5 – 20P/100 = 1300
or, (72P-20P)/100 =1300
or, 52P = 1300 × 100
:. P=(1300 × 100)/52
= Rs.2500
Shortcut Method:
Suppose Raja invested Rs.100 in scheme X.
Then,
According to the question:
52 =Rs.1300
:. P = 100 = (1300/52) x 100 =Rs.2500
Answer is: A)
10). The distance covered in (9 am – 8 am) is 1 hour by train “X”=53 × 1 = 53 km Remaining distance 569 – 53 = 516 km
Relative speed 76 + 53 =129 kmph
:. They meet after (516/129) = 4 hours
Hence they meet at (9 am + 4 hours) = 1 pm
Answer is: B)