Your Answer : (Not Answered)

Correct Answer : D

X + 21 = 50.

Let X have tens digit \(a\) and units digit \(b\). Reversing adds 63:

\[ \begin{aligned} (10b + a) - (10a + b) &= 9(b - a) = 63 \\ b - a &= 7,\quad a + b = 11 \\ a &= 2,\ b = 9 \end{aligned} \]

So X = 29 and X + 21 = 50. The option 29 is X itself, not X + 21, and 113 adds 21 to the reversed number 92.

Check: 92 - 29 = 63 and 2 + 9 = 11. In general, reversing a two-digit number changes it by 9 times the difference of its digits, a useful shortcut for such questions.

Your Answer : (Not Answered)

Correct Answer : D

Solve for the radius, taking \( \pi = \tfrac{22}{7} \).

\[ \frac{4}{3}\pi r^{3} = 4851 \]

\[ r^{3} = \frac{4851 \times 3 \times 7}{4 \times 22} = \frac{101871}{88} = 1157.625 \]

\[ r = \sqrt[3]{1157.625} = 10.5 \text{ cm} \]

\[ d = 2r = 21 \text{ cm} \]

The question asks for the diameter, so the radius of 10.5 cm must be doubled - stopping at the radius is the intended slip.

Your Answer : (Not Answered)

Correct Answer : A

Correct answer: ₹20.40

The price of a mixture is the total cost divided by the total quantity - a weighted average rather than a simple one. The total cost is \[ 20 \times 24 + 30 \times 18 = 480 + 540 = 1020, \] and the total quantity is 50 kg, so \[ \text{price} = \frac{1020}{50} = 20.40 \text{ per kg}. \] The distractor 21 is the simple average of 24 and 18, which would be correct only if equal quantities were mixed. Because more of the cheaper wheat is used, the mixture price must lie below the midpoint - and noticing that rules out both 21 and 22 at once. This is the direct problem; alligation solves the inverse one, finding the ratio when the mixture price is given. The two are the same relation read in opposite directions, and it is worth being able to move either way: \[ \text{mean} = \frac{q_{1}p_{1} + q_{2}p_{2}}{q_{1} + q_{2}}. \]

Your Answer : (Not Answered)

Correct Answer : C

Present total age of the members = 26(5) = 130 years 

Present age of the youngest member = 10 years
Present total age of the remaining four members = 130 - 10 = 120 years

Their average age at the time of the birth of the youngest member =  \(\frac{120-(4*10)}{4}\)

= 30 - 10 = 20 years

Your Answer : (Not Answered)

Correct Answer : A

Correct answer: Conclusion (d) Only

This set’s code reads \(\&\) as “not greater than”, so \(\le\); \(*\) as “not smaller than”, so \(\ge\); \(\%\) as “neither greater than nor equal”, so \(<\); \(\$\) as “neither smaller than nor equal”, so \(>\); and \(@\) as \(=\). The statements become \( P < R \), \( S > T \), \( R \le S \), \( K \le S \), \( G \ge K \) and \( S > M \).

(d) \( S \ge K \): this is the fourth statement read the other way round - \( K \le S \) is exactly \( S \ge K \). True.

The other three all founder on the same feature: S is a high point, with R, K, T and M all at or below it, so any two of them are on separate branches beneath it.

(a) \( P \le K \): P sits below R, K sits below S. Not determined.

(b) \( R \ge M \): both are below S. Not determined.

(c) \( S = G \): G stands above K, which sits below S, so G could be anywhere from K upwards - below S, equal to it, or above. Not determined.

Only (d) follows, and it follows because it merely restates a premise. Scanning the conclusions for a restated statement before doing any chaining is usually the fastest first move on these.

Your Answer : (Not Answered)

Correct Answer : D

Correct answer: Neither I nor II follows

Course 1 would suspend officers on an allegation that has not been examined, which is premature. Course 2 would have the central bank stop issuing directives altogether, which mistakes the offence for the rule. What is called for is an inquiry, and neither course provides it. Neither follows.

Your Answer : (Not Answered)

Correct Answer : C

The missing letters are CACAC.

Filling the blanks in order gives the groups

ABCB, BCAC, CABA, ABCB

Each group is a rotation of ABC followed by its own middle letter: ABC + B, BCA + C, CAB + A, and then the cycle returns to ABC + B.

The other options break a group: CCAAC makes the second group BCCC, CBABC makes it BCBC, and BCCAB makes the very first group ABBB.

Your Answer : (Not Answered)

Correct Answer : A

Correct answer: 90

Every gap is the same: the differences run 21, 21, 21, so the common difference is 21. Applying it once more to the final term, 69 + 21 gives 90. As a check, subtracting 21 from the answer returns 69, the term before it, and repeating that recovers the whole series. Arithmetic progressions appear more often than any other family in this topic, so they are worth eliminating quickly before looking for anything subtler.

Your Answer : (Not Answered)

Correct Answer : A

Correct answer: 13

The terms are the prime numbers in order - 2, 3, 5, 7, 11 - each divisible only by itself and 1. The next prime after 11 is 13; 12, 14 and 15 all have smaller factors.

Your Answer : (Not Answered)

Correct Answer : C

Correct answer: Data inadequate

The fractions apply to two different groups, so the combined fraction depends on how many girls and boys there are. With equal numbers it would be \[ \tfrac{1}{2}\left(\tfrac{1}{5}+\tfrac{1}{8}\right) = \tfrac{13}{80}, \] but with twice as many girls as boys it is different again, and nothing in the question fixes the ratio. Adding the fractions or their numerators and denominators has no justification at all.

Your Answer : (Not Answered)

Correct Answer : C

The new alphabet series is :
B  A  D  C  F  E  H  G  J  I  L  K  N
M  P  O  R  Q  T  S  V  U  X  W  Z  Y
The seventeenth letter from the right is I

Your Answer : (Not Answered)

Correct Answer : A

Correct answer: Grandson

This man’s son’s sister is simply the man’s daughter, and she is the speaker’s mother-in-law - that is, her husband’s mother. So the man is her husband’s maternal grandfather, and the husband is the man’s grandson.

Your Answer : (Not Answered)

Correct Answer : A

The correct sequence is Preserve, protect and defend the Constitution and the law.

Under Article 60, the President swears or affirms to faithfully execute the office of President, and to the best of his or her ability preserve, protect and defend the Constitution and the law, and to devote himself or herself to the service and well-being of the people of India.

The other options use the same three verbs in a different order. The order is fixed by the text of the oath, so any rearrangement is wrong. The same three verbs in this order appear in the Governor's oath under Article 159.

Your Answer : (Not Answered)

Correct Answer : C

The magnetism at the centre of a bar magnet is zero.

The magnet behaves as though its poles were concentrated near the ends, and at the midpoint the effects of the two opposing poles cancel. Iron filings therefore cling to the ends and not to the middle. The midpoint is called the neutral region.

Your Answer : (Not Answered)

Correct Answer : A

Newton's first law is the law of inertia.

It states that a body remains at rest or in uniform motion in a straight line unless an external force acts on it, so it defines inertia and identifies the inertial frames in which the other two laws hold.

Your Answer : (Not Answered)

Correct Answer : D

Glenn McGrath was nicknamed Pigeon, a reference to his very thin legs when he first arrived in state cricket.

He took 563 Test wickets, more than any other fast bowler at the time of his retirement in 2007.

Your Answer : (Not Answered)

Correct Answer : C

They are given for outstanding contribution to science.

The Shanti Swarup Bhatnagar Prize, instituted by CSIR in 1958 and named after its founding director, is India's highest science honour, given annually to scientists under 45 in seven disciplines.

Your Answer : (Not Answered)

Correct Answer : B

The coalition is the Under 2 Coalition.

The Under2 Coalition is a group of state, provincial and regional governments, for which The Climate Group acts as secretariat, committed to cutting greenhouse gas emissions in line with keeping global warming well under 2 °C. Its members are sub-national, not national, governments.

EP100 is a Climate Group initiative of businesses committed to energy productivity. 'Kyoto Coalition' and 'Climate Coalition' are not the name of this sub-national alliance.

Your Answer : (Not Answered)

Correct Answer : D

They turn invasive and cause decline or extinction of indigenous species.

An alien species introduced by accident, for example in ships' ballast water or with imported grain, often arrives without the predators, parasites and diseases that kept it in check at home. It can then spread rapidly and out-compete, prey on or infect native species. Lantana, water hyacinth and Parthenium in India are examples; invasive species are one of the main causes of biodiversity loss.

A decrease of the alien species is the opposite of what usually happens to a successful invader. 'Increase in habital' and 'cause increase species' do not describe any recognised effect of invasion.

Your Answer : (Not Answered)

Correct Answer : C

The greenhouse gas present in the largest concentration among those listed is carbon dioxide.

Carbon dioxide is present at about 420 parts per million, far more than nitrous oxide (about 0.34 ppm) or the chlorofluorocarbons and hydrofluorocarbons, which are measured in parts per trillion. (Water vapour is more abundant still, but it is not among the options.)

Concentration is different from warming power per molecule: CFCs and HFCs are thousands of times more potent than CO₂ but present in tiny amounts.