Correct Answer: 40

Solution : Given,
The mixture of alcohol and water = 80 litres
Initial alcohol concentration = 60%
Amount of alcohol in 80 litres of mixture = 60% of 80
= $\frac{60}{100}\times80$ = 48 litres
Also, 40 percent alcohol in the new mixture after the addition of X litres of water.
So, according to the question,
48 = $\frac{40}{100}$ × (80 + X)
⇒ 48 = $\frac{2}{5}$ (80 + X)
⇒ 240 = 2(80 + X)
⇒ 240 = 160 + 2X
⇒ 2X = 80
⇒ X = 40
Hence, the correct answer is 40.

Correct Answer: William Gaud

Solution : The answer is William Gaud.

On March 8, 1968, William S. Gaud, the administrator of the U.S. Agency for International Development (USAID), introduced the term "Green Revolution." In his speech, he highlighted the proliferation of these novel technologies in agriculture, stating that they harboured the potential for a transformative agricultural revolution.

Correct Answer: Article 51A (c)

Solution : The correct option is Article 51A (c).

Article 51A(c) of the Indian Constitution outlines one of the fundamental duties of citizens. This clause emphasises the responsibility of citizens to contribute to the safeguarding of the sovereignty, unity, and integrity of the nation. The inclusion of fundamental duties in the Constitution is aimed at promoting a sense of responsibility and commitment among citizens towards the larger goals of the nation.

Correct Answer: 290

Solution : The total number of teachers in all these five universities is 720.
J1 = The value of the average number of teachers in B and C
From the given pie- chart,
⇒ Number of teachers in University B $=\frac{30°}{360°}\times720=60$
⇒ Number of teachers in University C $=\frac{120°}{360°}\times720=240$
$\therefore$ Average $=\frac{60+240}{2}=150$
J2 = The value of the average number of teachers in A and E
⇒ Number of teachers in University A $=\frac{40°}{360°}\times720=80$
⇒ Number of teachers in University E $=\frac{100°}{360°}\times720=200$
$\therefore$ Average $=\frac{200+80}{2}=140$
So, J2 + J1 = 150 + 140 = 290
Hence, the correct answer is 290.

Correct Answer: 36.5%

Solution :  Total students in P and R = Students in P + Students in R
=  8000 + 15000 = 23000
Students in Mathematics in P and R =
=  30% of 8000 + 40% of 15000
=  0.3 × 8000 + 0.4 × 15000
=  2400 + 6000 = 8400
Required percentage = $\frac{\text{Students in Mathematics in P and R​}}{\text{Total students in P and R}}$×100%
= $\frac{\text{8400​}}{\text{23000}}$×100%
= 36.5%
Hence, the correct answer is 36.5%.

Correct Answer: To work fast

Solution : The second option is correct.

The given idiom, work against the clock, means to do it as fast as possible and try to finish it before a certain time.

Therefore, the correct answer is to work fast.

Correct Answer: 2.1-2.9

Solution : The correct answer is 2.1-2.9.

According to the 2011 Census, India's Total Fertility Rate (TFR)* was 2.4 per woman. The majority of Indian states now have fertility rates far below the replacement level of 2.1, and the nation is rapidly reaching the replacement level itself, according to recent research and surveys.

Correct Answer: India

Solution : The correct answer is India.

With its lush meadows and tropical woods, India is the only country in the world where one may witness both tigers and lions roaming freely. The country is home to both species, but they never come into contact in the wild because lions are restricted to Gir Forest National Park.

Correct Answer: mild sweet due to low sulphur content

Solution : The correct option is mild sweet due to low sulphur content.

Sweet crude oil is a type of oil that contains only 1% sulphur. The term "sweet" is used to describe its mild and pleasant smell, unlike sour crude, which has a higher sulphur content and a less pleasant odour. Refineries prefer sweet crude oil because it requires less processing to remove sulphur impurities, resulting in cleaner end products.

Correct Answer: and on many evenings he helps me with the

Solution : The correct choice is the second option.

Explanation: The sentence requires consistency in verb tense between the two clauses connected by "and". The initial part of the sentence, "he lights his pipe", is in the present tense. Therefore, to maintain consistency, the verb in the second clause should also be in the present tense.

So, the correct sentence would be: "He lights his pipe, and on many evenings he helps me with the dishes."