Correct: C. C

B and C must occupy consecutive seats with B immediately before C. If B and C occupied seats two and three, A would be forced to an end seat, which violates the condition, so B and C must occupy seats one and two. Therefore C must sit second, with A third and D fourth.

Correct: A. It is 4% lower

Assume the original price is 100. A 20% increase makes it 120, and reducing 120 by 20% subtracts 24, leaving 96. The final price is therefore 4% lower than the original because equal percentage increases and decreases are applied to different base amounts.

Correct: B. 48

The differences between consecutive terms are 5, 7, 9, and 11. The differences increase by 2 each time, so the next difference is 13. Adding 13 to 35 gives 48.

Correct: C. R

P must occupy the first position, leaving positions two, three, and four for Q, R, and S. Because Q must stand immediately before R and S cannot be last, Q and R must occupy positions three and four. Therefore R must be last.

Correct: C. 120

After a 25% increase, the new value equals 125% of the original value. Therefore the original number is 150 ö 1.25 = 120. Checking the result, 25% of 120 is 30 and 120 + 30 equals 150.

Correct: B. 15

The ratio 3:5 contains 8 equal parts in total. Dividing 40 by 8 gives 5 balls per part, and the red balls account for 3 parts. Therefore there are 3 ? 5 = 15 red balls.

Correct: C. 6 hours

The total work requires 3 ? 12 = 36 machine-hours. With 6 identical machines working together, the required time is 36 ö 6 = 6 hours. This is an inverse-proportion relationship because increasing the number of equally efficient machines reduces the time required.

Correct: B. 42

The differences are 4, 6, 8, and 10, so the next difference is 12. Adding 12 to 30 gives 42.

Correct: C. 20

The ratio contains 4 + 5 = 9 equal parts, so each part represents 45 ö 9 = 5 students. Boys account for four parts, giving 4 ? 5 = 20 boys.

Correct: C. 4 hours

The task requires 5 ? 8 = 40 machine-hours of work. Ten machines therefore need 40 ö 10 = 4 hours to complete it.

Correct: C. 80

After a 20% decrease, 80% of the original number remains. Dividing 64 by 0.8 gives the original value of 80.

Correct: A. EPH

Each letter is replaced by the next letter of the alphabet, so D becomes E, O becomes P, and G becomes H. Therefore DOG is coded as EPH.

Correct: C. 12 years

After x years, their ages will be 36 + x and 12 + x, and the condition is 36 + x = 2(12 + x). Solving gives x = 12, so the father will be 48 when the son is 24.

Correct: B. 25%

The profit is $250 - $200 = $50. Dividing the $50 profit by the $200 cost price gives 0.25, or 25%.

Correct: B. 15

Each handshake represents a unique pair of people, and six people form 6 ? 5 ö 2 = 15 pairs. Division by two is necessary because counting from each person's perspective would count every handshake twice.

Correct: C. 20 litres

The car uses 8 ö 120 = 1/15 litre per kilometre. For 300 km, it therefore needs 300 ö 15 = 20 litres.

Correct: C. 30%

The increase is 260 - 200 = 60. Dividing 60 by the original value 200 gives 0.30, or 30%.

Correct: C. 9 days

The project requires 12 ? 15 = 180 worker-days of effort. With 20 workers, the time needed is 180 ö 20 = 9 days.

Correct: C. 100

The numbers 8, 27, 64, and 125 are 2?, 3?, 4?, and 5? respectively. The number 100 is not a perfect cube, so it does not follow the pattern.

Correct: C. 24

For three consecutive integers, the middle value equals their average. Dividing 72 by 3 gives 24, so the integers are 23, 24, and 25.

Correct: B. 48 km

The first part covers 18 ? 2 = 36 km and the second covers 12 ? 1 = 12 km. Adding the distances gives 48 km in total.

Correct: B. No laptop is switched on

Every laptop in the room belongs to the group of devices, and no device in the room is switched on. Therefore none of the laptops in that room can be switched on.

Correct: B. 12

Let the daughter's age be x, making the mother's age 3x. Then x + 3x = 48, so 4x = 48 and x = 12.

Correct: C. 46

The differences are 3, 6, 9, and 12, which increase by 3 each time. The next difference is 15, so 31 + 15 = 46.

Correct: C. 36

Subtracting 6 from 15 gives 9, which is the number after division by 4. Multiplying 9 by 4 gives the original number, 36.

Correct: C. 70

If three fifths of a number equals 42, one fifth equals 42 ö 3 = 14. Multiplying 14 by 5 gives the whole number, 70.

Correct: C. 95

Each term is twice the previous term plus 1. Applying the rule to 47 gives 47 ? 2 + 1 = 95.

Correct: C. $60

If B has one part, A has two parts, making three equal parts altogether. Each part is $90 ö 3 = $30, so A has 2 ? $30 = $60.

Correct: C. 15 m/s

To pass a pole completely, the train travels a distance equal to its own length of 150 metres. Dividing 150 metres by 10 seconds gives a speed of 15 m/s.

Correct: C. 161

Each term is twice the previous term minus 1. Applying the rule to 81 gives 81 ? 2 - 1 = 161.

Correct: C. 32

Six numbers with an average of 25 have a total of 6 ? 25 = 150. Subtracting the known total of 118 leaves 32.

Correct: B. 40

The successive decreases are 4, 8, 12, and 16. The next decrease is 20, so 60 - 20 = 40.

Correct: B. 18

Nine workers make 27 tables, so one worker makes 3 tables in the same three-day period. Six workers therefore make 6 ? 3 = 18 tables.

Correct: B. Rina is not a painter

If every painter is creative, anyone who is not creative cannot be a painter. Since Rina is stated to be not creative, she cannot belong to the painter group.

Correct: C. $333.33

After a 20% increase, the final price is 120% of the original. Dividing $400 by 1.20 gives approximately $333.33.

Correct: A. 5 km

The northward and eastward movements form perpendicular sides of a right triangle. Using the Pythagorean relationship gives û(4ý + 3ý) = û25 = 5 km.

Correct: B. $400

Seven ratio parts correspond to $280, so one part equals $40. The total contains ten parts, giving 10 ? $40 = $400.

Correct: C. 45

The ratio contains seven total parts. Each part is 63 ö 7 = 9, so the larger number is 5 ? 9 = 45.

Correct: C. $690

Fifteen percent of $600 is $90. Adding the profit to the cost gives a selling price of $690.

Correct: C. 23

The increases are +1, +2, +3, +4, and +5. The next increase is +6, so 17 + 6 = 23.

Correct: C. 32

The original four people have a combined age of 4 ? 30 = 120. Adding 40 gives 160, and dividing by five gives a new average of 32.

Correct: A. TPVUI

Each letter advances one position in the alphabet. S becomes T, O becomes P, U becomes V, T becomes U, and H becomes I, producing TPVUI.

Correct: C. 10-Jul

The decimal values are 0.60, 0.625, 0.70, and approximately 0.667. Therefore 7/10 is the largest fraction.

Correct: B. 12

The total work is 8 ? 15 = 120 person-days. Completing 120 person-days of work in 10 days requires 120 ö 10 = 12 people.

Correct: B. 12

Maya's position is counted in both the front and back totals. The number of people is therefore 8 + 5 - 1 = 12.

Correct: C. 15%

The decrease is 500 - 425 = 75. Dividing 75 by the original 500 gives 0.15, or 15%.

Correct: C. $120

The ratio contains 2 + 3 + 5 = 10 parts. Each part equals $240 ö 10 = $24, so the largest share is 5 ? $24 = $120.

Correct: C. 53

The differences are 4, 6, 8, and 10. The next difference is 12, so 41 + 12 = 53.

Correct: A. 10 km

The two movements form perpendicular sides of a right triangle measuring 6 km and 8 km. The direct distance is û(6ý + 8ý) = û100 = 10 km.

Correct: B. Daughter

Ravi's mother's only son is Ravi himself because he has no brothers. The woman is therefore the daughter of Ravi.

Correct: B. Father

The woman's father's father is her paternal grandfather. The only son of that grandfather is the woman's father.

Correct: D. E

The clockwise order begins A, B, C, D, leaving E in the final seat before returning to A. Therefore E sits immediately counterclockwise from A.

Correct: C. Wednesday

R must be Thursday, leaving Tuesday and Wednesday for S and Q after P occupies Monday. Because S is immediately before Q, S must be Tuesday and Q must be Wednesday.

Correct: B. 40

Adding the two groups gives 28 + 22 = 50, but the 10 people who like both have been counted twice. Subtracting the overlap gives 50 - 10 = 40 people who like at least one drink.

Correct: C. 2-Jan

The equally likely outcomes are HH, HT, TH, and TT. Exactly one head occurs in HT and TH, giving 2 favourable outcomes out of 4, or 1/2.

Correct: B. Painting : Painter

A book is created by an author, and a painting is created by a painter. The other pairs describe performance, attendance, or use rather than creation.

Correct: A. More buses could reduce overcrowding

The recommendation makes sense only if adding buses can help reduce the stated overcrowding problem. The other choices are not required for the argument to work.

Correct: B. The campaign may have contributed to the increase

The timing suggests the campaign may have contributed to the increase, but the information does not prove that it caused all of the additional traffic. Other factors could also have influenced website visits.

Correct: C. Both I and II together

Statement I alone contains two unknowns, so x cannot be uniquely determined. Combining it with statement II gives x + 8 = 20, so x = 12.

Correct: A. I alone

Any integer divisible by 4 must also be divisible by 2, so statement I alone guarantees that n is even. Being greater than 10 does not determine whether an integer is odd or even.

Correct: C. East

Facing north, the first right turn changes the direction to east. The next right turn changes it to south, and the final left turn changes it back to east.