APTITUDE ANSWERS
1.SOLUTION:
Let the number be x.
Hence,2x=12+(x/2)=8
ANSWER: c)8
2.SOLUTION:
consider a 3 digit number 201
reversing102
201-102=99divisble by 99.
ANSWER: d)99.
3.SOLUTION:
Let the cost of apples be x.
Let the cost of mangoes be y.
Let the cost of oranges be z.
->3x+2y+4z=43(1)
->5x+3y+6z=66(2)
Solve the equations by eliminating y and z.
ANSWER: c)Rs.3
4.SOLUTION:
3x+4y=24(1)
15x+20y=8k(2)
Solve the equation by eliminating either x or y or both.
ANSWER: d)15
5.SOLUTION:
Given, speed=60 km/hr 60 km in 1 hr1 km in 1 minute1 km in 60 seconds
1 km in 60 seconds1000m in 60 seconds? M in 9 seconds(1000/60)*9=150 m
ANSWER: d)150 m
6.SOLUTION:
Given, ratio of earnings to expenditureA5:3,B7:6
Given,if savings of A is double than that of B.
A earns 5 and uses 3,B earns 7 and uses 6A saves twice than B
Total earnings5+712
Total expenditures3+69
Total ratio12:94:3
ANSWER: a)4:3
7.SOLUTION:
Let the salaries of 2 persons be x and y.
x=y
x+10%=y-10%
there is no change in salaries.
ANSWER: c)no change.
8.SOLUTION:
Given, price reduced to Rs.72.
Let x be the price.
x-0.1x=720.9x=72x=720/9x=80
ANSWER: d)80.
9.SOLUTION:
Let the percentage be x.
Start price
end price
Week 1
80
80(1+x)
Week 2
80(1+x)
80(1+x)(1+x)
80(1+x)(1+x)-80=105.80-80
80(1+x)(1+x)=105.80(1+x)2=105.80/80x=15%
ANSWER: c)15%.
10.SOLUTION:
Let the two no's be a and b.
then we have ab = 12^2
and b^2 = 96*a
or b^3 = 12^2 * 96 = (24)^3
so b = 24 and a = 6
So greater among two is 24.
ANSWER: b)24
11.SOLUTION:
Given, p+q/r=q+r/p=p+r/q = k
We know that,
a/b=c/d=e/f => (a+c+e)/(b+d+f)
Therefore,
((p+q)+(q+r)+(p+r)) / (r+p+q) = k
(2p+2q+2r) / (p+q+r) = k
2(p+q+r) / (p+q+r) = k
2/1 = k
k=2
ANSWER: c)2
12.SOLUTION:
TOTAL
PG
UG
MALE
1000
520
480
740
FEMALE
260
Total UG’S=1000-520=480
Let the number of female UG’s be x.
x+(x+38)=480
2x=480-38=442
x=442/2
x=221
No of girls in UG=221
Boys in UG=480-221=259
Percentage of male UG’s(259/740)*100=35%
ANSWER: d)35%
13.SOLUTION:
Given, 10% of a=b% of 200
10%a=b%200
a/b=20
ANSWER: a)20
14.SOLUTION:
Any number to be divisible by 11 is given as,
Sum of the digits in odd position should be equal to sum of the digits in even position or
difference of sum of the digits of odd positions and sum of the digits of even positions should be
divisible by 11.
Hence the trial and error method is involved.Among the four options the number 123321
satisfies the condition.
1+3+2=2+3+1=6
ANSWER: c)123321
15.SOLUTION:
Formula: lateral surface area=2h(d+w)2(6)(5+4)108 sq.cm
ANSWER: a)108 sq.cm
16.SOLUTION:
R – radius
;
h – sagitta
;
– plane angle
r – apothem
Length of the chord , a = 2
a=2
=2
=2
= 2(4)
a=8
ANSWER: d)8 cm
17.SOLUTION:
Formula: angle=(1/2)|60H-11M|(1/2)|(60(3)-11(30))|75 deg
Where M is minutes and H is hours.
ANSWER: a)75 degrees
18.SOLUTION:
A
B
100
90
100
C
80
Total distance run by C is =(90*80)/100=72
A’s 100m run=B’s 90 m run.
difference between A and C is=100-72=28 m
ANSWER: c)28 m
19.SOLUTION:
Speed of A=3x
Speed of B=2x
B starts at 8:00
A starts at 9:00
At 3x A reaches 11:00 am in 1 run
At 2x B reaches 10:00 am in 1 run,but starts 1 hr ahead.
they both meet at 11:00 am
ANSWER: b)11:00 am
20.SOLUTION:
Speed=total distance/total time=260/90=28.89
ANSWER: c)28.89m/s (or) 8.02 km/hr.
21.SOLUTION:
For managing, A received = 5% of Rs. 7400 = Rs. 370.
Balance = Rs. (7400 - 370) = Rs. 7030.
Ratio of their investments = (6500 x 6) : (8400 x 5) : (10000 x 3)
= 39000 : 42000 : 30000
= 13 : 14 : 10
B’s share=(7030*(14/37))=Rs.2660
ANSWER: b)Rs.2660.
22.SOLUTION:
On 31st December, 2005 it was Saturday.
Number of odd days from the year 2006 to the year 2009 = (1 + 1 + 2 + 1) = 5 days.
On 31st December 2009, it was Thursday.
ANSWER: c)Thus, on 1st Jan, 2010 it is Friday.
23.SOLUTION:
Let the ages of children be x, (x + 3), (x + 6), (x + 9) and (x + 12) years.
Then, x + (x + 3) + (x + 6) + (x + 9) + (x + 12) = 50
5x = 20
x = 4.
Age of the youngest child = x = 4 years.
ANSWER: a)4 years.
24.SOLUTION:
Let the son's present age be x years. Then, (38 - x) = x
2x = 38.
x = 19.
Son's age 5 years back (19 - 5) = 14 years.
ANSWER: a)14 years.
25.SOLUTION:
L.C.M. of 21, 36, 66 = 2772.
Now, 2772 = 2 x 2 x 3 x 3 x 7 x 11
To make it a perfect square, it must be multiplied by 7 x 11.
So, required number = 22 x 32 x 72 x 112 = 213444
ANSWER: a)213444.
26.SOLUTION:
Average speed=[(total distance)/(total time taken)]
Given, average speed=60 kmph
Time taken=3 hrs
total distance=60*3=180 km
27.SOLUTION:
P5 DAYS ; Q6 DAYS ;R8 DAYS
5x+6x+8x=295x is approximately equal to 15R’s share8(15)120
ANSWER: b)Rs.120.
28.SOLUTION:
1/20+(1/4*1/20)x=1
x=5
(1/20)+(5/80)x=1
x(9/80)=1x=80/9
ANSWER: 80/9 days
29.SOLUTION:
31+49=80
34+46=80
37+43=80
40+52=92
80+80+80+92=332/8=41.5
ANSWER: a)41.5
30.SOLUTION:
(1/20)+[(1/25)]x=25%(20)
x=5
ANSWER: a)5 lts