4
Let the digits be Thousands = a, Hundreds = b,
Tens = c, Units = d.
Given: a + b + c = 15, b + c + d = 16 and c = d +
6.
So (c, d) can be (7, 1), (8, 2) or (9, 3).
The corresponding values of b can be 8, 6 and 4
respectively. Further corresponding values of a can
be 0, 1, and 2 respectively.
But a must be ≥ 1.
Therefore, largest possible value will be = 2493
and smallest possible value will be = 1682.
Hence, required difference = 2493 – 1682 = 811.
2
Let average salary of engineers and managers be
x and y respectively.
Total original salary = 30 × 60000 = Rs. 18,00,000
Managers get 20% increase; engineers' salaries
remain unchanged.
Overall average increases by 5%, therefore, new
average = Rs. 63,000.
New total salary: 30 × 63000 = Rs. 18,90,000
Increase in total salary = 1890000 – 1800000
= Rs. 90,000
Increase comes only from managers: 5 × 0.2y = y
or, y = Rs. 90,000.
Original total salary is 5y + 25x = 18,00,000
Hence, 5 × (90000) + 25x = 1800000 or,
x = Rs. 54,000.
1
Let marked price = M
In January, SP = 0.8M
In February, SP = 0.9M
In March, SP = 0.95M
In April, SP = M
Total profit = 120 × 0.8M + 135 × 0.9M + 150 ×
0.95M + 165 × M – 570 × 240 = 138825
Simplifying: 525M – 136800 = 138825 or, 525M
= 275625 or, M = Rs. 525
126
Given: AB = AC = 50 cm, BC = 80 cm
Triangle is isosceles, therefore, the altitude drawn
from the vertex angle (between the two equal sides)
to the base acts as a perpendicular bisector.

Area of the triangle ABC
= 1/2 × 80 × 30
= 1200 cm2.
Altitudes:
ha = 2 × Area / BC = 30 cm
hb = 2 × Area / AC = 2400 / 50 = 48 cm
hc = 2 × Area / AB = 48 cm
Hence, the sum of altitudes = 30 + 48 + 48
= 126 cm.
1
As per the question.

Since AB = AC, therefore, ∠ABC = ∠ACB and its
given ∠ACB = ∠AEB.
This implies that points C, B, E, A lie on a common
circle (same angle subtended by chord AB). So A,
B, C, E are concyclic.
Since D lies inside the circle and AD is extended
to E: DA × DE = DB × DC (Power of Point property)
But in an isosceles triangle with AB = AC, the
altitude from A to BC also bisects BC. Hence D
lies on the perpendicular bisector only if DB = DC.
So, DB = DC
Therefore, DB × DC = DB²
Thus, AD × DE = DB²
DE = AE – AD = AE – 8
So 8 × (AE – 8) = DB²
In triangle ABD, AB = 12 cm and AD = 8 cm.
Using Pythagoras:
DB² = AB² – AD² or, DB² = 12² – 8² = 80
Hence, 8(AE – 8) = 80 or, AE = 18 cm.

3


1

4
Let initial speed = v km/h and let total distance
= D
Total scheduled time = 5 pm to 11 pm = 6 hours.
So, D = 6v
Case 1: He drives at speed v first, then stops for
20 minutes or 1/3 hours, then drives at speed
(v + 3). Let time driven at speed v be 't' hours.
Then remaining driving time after stop = 6 – t –
1/3 = 17/3 – t
vt + (v + 3)(17/3 – t) = D …(1)
Substitute: D = 6v
⇒ vt + (v + 3)(17/3 – t) = 6v
⇒ –3t + 17v/3 + 17 = 6v
⇒ t = (51 – v)/9 …(A)
Case 2: He drives at speed v first, then stops for
30 minutes or 1/2 hours, then drives at speed
(v + 5). Let time driven at speed v be 't' hours.
Time after stop: 6 – t – 1/2 = 11/2 – t
So vt + (v + 5)(11/2 – t) = 6v …(2)
⇒ vt – vt – 5t + 11v/2 + 55/2 = 6v
⇒ –5t + 11v/2 + 55/2 = 6v
⇒ t = (55 – v)/10 …(B)
Equate (A) and (B):
⇒ (51 – v)/9 = (55 – v)/10
⇒ v = 15 km/h
272
Let initial number of coins in A and B be 17x and
7x respectively.
After shifting 108 coins, number of coins in
A = 17x – 108 and in B = 7x + 108.
So (17x – 108)/(7x + 108) = 37/20
⇒ 20(17x – 108) = 37(7x + 108)
⇒ 340x – 2160 = 259x + 3996
⇒ 81x = 6156 ⇒ x = 76
So, after first shift:
A = 17 × 76 – 108 = 1184
B = 7 × 76 + 108 = 640
Difference = 1184 – 640 = 544
To make ratio 1:1, shift half the difference.
Required shift = 544/2 = 272
397
Given: p + q + r = 900 and r is a perfect square
between 150 and 500.
Possible r values: 169, 196, 225, 256, 289, 324,
361, 400, 441, 484
We have 0.3q ≤ p ≤ 0.7q, or q + 0.3q ≤ p + q ≤ q +
0.7q or 1.3q ≤ p + q ≤ 1.7q.
Also, we can rewrite p + q = 900 – r. Therefore,
1.3q ≤ 900 – r ≤ 1.7q.
Since the extreme values (maximum and
minimum) of p depend on the value of q (0.3q and
0.7q), we can maximise or minimise r to find the
extreme values of p.
Since 1.3q ≤ 900 – r, the minimum possible value
of q would be when 1.3q = 900 – r and when r is
maximum. The maximum value of r is 484. We get
1.3q = 900 – 484, or q = 320.
This gives the minimum possible value of p as
0.3 × 320 = 96.
Since 900 – r ≤ 1.7q, the maximum possible value
of q would be when 900 – r = 1.7q and when r is
minimum. The minimum value of r is 169. We get
1.7q = 900 – 169 or q = 430.
This gives the maximum possible value of p as
0.7 × 430 = 301.
The sum of the maximum and minimum values of
p is 96 + 301 = 397.
1
Given: AB || DC, AD ⊥ AB, AB = 3DC and Radius
of incircle = 3 cm
Let DC = x ⇒ AB = 3x
Since circle touches both parallel sides, Height
= 2r = 6.
Area = 1/2 × (AB + DC) × height
= 1/2 × (3x + x) × 6 = 12x
For a tangential trapezium: Sum of parallel sides
= sum of non-parallel sides
⇒ AB + DC = AD + BC
⇒ 4x = 6 + BC
⇒ BC = 4x – 6
Using right triangle: BC² = (AB – DC)² + AD²
⇒ (4x – 6)² = (2x)² + 36
⇒ 16x² – 48x + 36 = 4x² + 36
⇒ 12x² – 48x = 0
⇒ x = 4
Hence, the area = 12x = 48 sq. cm.
16
Let x litres be transferred from A to B.
After first transfer, A has 60 – x litres of alcohol
and B has 'x' litres of alcohol and 60 litres of water.
Note: Fraction of alcohol in B = x / (60 + x) and,
Fraction of water in B = 60 / (60 + x)
Again 'x' litres are taken from B and poured back
into A.
Alcohol transferred back to A = x × x / (60 + x)
Water transferred back to A = x × 60 / (60 + x)
Therefore, alcohol in A = (60 – x) + x² / (60 + x) and
water in A = 60x / (60 + x).
⇒ [(60 – x)(60 + x) + x²] / 60x = 15/4
⇒ (3600 – x² + x²) = 3600
⇒ 3600 / 60x = 15 / 4
⇒ 60 / x = 15 / 4
⇒ x = 16
Hence, initially 16 litres was transferred from
A to B.
3
Let rates of pipes A, B and C be 4k, 9k and 36k.
Since Pipe A alone fills the tank in 15 hours, so,
rate of A = 1/15 tank per hour.
⇒ 4k = 1/15 ⇒ k = 1/60
Combined rate of all three pipes
A + B + C = (4k + 9k + 36k) = 49k = 49/60 tank
per hour.
Time required = 1 ÷ (49/60) hours = 60/49 hours
= (60/49) × 60 minutes ≈ 73.47 minutes
Hence, the nearest option = 73 minutes.

1
Given: f(x) = (x2 + 3x)(x2 + 3x + 2)
⇒ √(f(x) + 1) = 9701
⇒ f(x) + 1 = 97012
⇒ f(x) = 97012 – 1
Let y = x2 + 3x
So y(y + 2) = 9700 × 9702
⇒ y2 + 2y – 9700 × 9702 = 0
⇒ y = 9700, –9702
When y = 9700:
⇒ x2 + 3x = 9700 or, x = 97, –100
When y = –9702:
⇒ x2 + 3x = –9702 will give no real value of x,
therefore, discarded.
Hence, the sum of real values of x = 97 – 100
= –3.
1
Number = 1050 + 1025 – 123 have 51 digits of which
51st and 26th digits are 1.
After subtracting 123, borrow comes from 26th digit
which is 1.
First three digits from right becomes 877 and digits
4th to 25th from right becomes 9. 26th digits
(initially 1) becomes 0.
Hence, the digit sum calculation = 1 + 9 × 22 + 8
+ 2 × 7 = 221.

1

112

1
As per the question, the rate of 1 member of
A = 1/200, rate of 1 member of B = 1/400,
And rate of 1 member of C = 1/40.
Initially, 2 members from A, 3 from B and 1 from C
are working.
Work done per hour = 2(1/200) + 3(1/400) + 1/40
= 1/100 + 3/400 + 10/400 = 17/400
Hence, work done in 23 hours = 23 × 17/400
= 391/400
Remaining work = 1 – 391/400 = 9/400
To finish in the next 1 hour, required rate = 9/400
After member from C leaves, working rate
= 2(1/200) + (3 + x)(1/400) = 1/100 + (3 + x)/400
Therefore, 1/100 + (3 + x)/400 = 9/400
⇒ 4 + 3 + x = 9
⇒ x = 2.
700
Let science, arts and commerce students be S,
A and C
Total students = S + A + C = 1500
Total fees = 1100S + 1000A + 800C = 1550000
⇒ 300S + 200A = 350000
⇒ 3S + 2A = 3500
Given A ⇒ S. To maximize S, take minimum A = S
Substitute and get: 3S + 2S = 3500 or,
⇒ S = 700.
65
4th + 7th + 10th terms = (a + 3d) + (a + 6d) +
(a + 9d) = 3a + 18d = 99
⇒ a + 6d = 33 … eq(1)
Sum of first 14 terms = 14/2 (2a + 13d)
⇒ 2a + 13d = 71 …eq (2)
Subtracting equations (1) and (2) and get:
⇒ d = 5 and a = 3
Sum of first 5 terms = 5/2 (2a + 4d) = 5/2 (6 + 20)
= 65
444
Let walking speed = v. Then, running speed = 1.4v.
Given: Time taken to walk B to C = time taken to
run B to A = 3.5 hours
Therefore, BC = 3.5v and BA = 3.5 × 1.4v = 4.9v.
Required time = walking A to B + running B to C
= 4.9v/v + 3.5v/1.4v
= 4.9 + 2.5 = 7.4 hours
Therefore, total time = 7.4 × 60 = 444 minutes.
1

We need to maximise a + d = 75 – 2x
Let e = 4, then x = 20
Hence, a + d = 75 – 40 = 35 is the maximum
possible value.