Correct Answer: has for

Solution : The most appropriate option is the first option.

Explanation: "The saving of certain wild animals from extinction has for many years been a problem." This choice implies that over an extended period (many years), the issue of saving wild animals from extinction has existed. In this sentence, the use of "has for" correctly signifies the ongoing nature of the problem of saving wild animals from extinction over many years.

Therefore, the correct answer is, has for.

Correct Answer: (a – b + c)²

Solution : We know that (x + y + z)² = (x² + y² + z² + 2xy + 2yz + 2zx)
Comparing the RHS of the above formula with the given expression, we get:
x = a, y = –b, and z = c
So, a² + b² + c² – 2ab – 2bc + 2ca = (a – b + c)²
Hence, the correct answer is (a – b + c)².

Correct Answer: $\frac{4}{9}$

Solution :
Given: $\Delta \mathrm{XYZ} \sim \Delta \mathrm{GST}$
$\left(\frac{\mathrm{YV}}{\mathrm{SD}}\right)=\left(\frac{\mathrm{XY}}{\mathrm{GS}}\right)$
$\therefore\left(\frac{\mathrm{YV}}{\mathrm{SD}}\right)^2=\left(\frac{\mathrm{XY}}{\mathrm{GS}}\right)^2=\left(\frac{\mathrm{2}}{\mathrm{3}}\right)^2=\frac{4}{9}$
Hence, the correct answer is $\frac{4}{9}$.

Correct Answer: NW-2

Solution : The correct answer is NW-2.

NW-2 is the most significant canal in India's North-East region. It also connects to mainland India via the Indo-Bangladesh Protocol, relieving congestion on the Siliguri Corridor (the sole direct link between mainland India and the North East). The canal is active, with permanent jetties in Pandu and Dhubri and floating jetties at eleven sites.

Correct Answer: + and ×

Solution : Given:
625 ÷ 25 + 7 × 318 – 112 = 381

Replace the given symbols in the options one by one with the original symbols in the given equation.
First option: – and +
= 625 ÷ 25 – 7 × 318 + 112
= 25 – 7 × 318 + 112
= 25 – 2226 + 112
= 137 – 2226
= –2089 ≠ 381
Second option: ÷ and +
= 625 + 25 ÷ 7 × 318 – 112
= 625 + 3.57 × 318 – 112
= 625 + 1135.26 – 112
= 1760.26 – 112
= 1648.26 ≠ 381
Third option: ÷ and –
= 625 – 25 + 7 × 318 ÷ 112
= 625 – 25 + 7 × 2.84
= 625 – 25 + 19.88
= 644.88 – 25
= 619.88 ≠ 381
Fourth option: + and ×
= 625 ÷ 25 × 7 + 318 – 112
= 25 × 7 + 318 – 112
= 175 + 318 – 112
= 493 – 112
= 381

So, only the fourth option satisfies the R.H.S. of the given equation. Hence, the fourth option is correct.

Correct Answer: 1206 and 1290

Solution : The correct options are 1206 and 1290.

The term "Delhi Sultanate" describes a group of five Muslim kingdoms that spent 320 years primarily centred in Delhi. The first Sultan of Delhi was Qutb ud-Din Aibak, who ruled from 1206 until 1290 under the Early Turkish Dynasty.

Correct Answer: 2 km/hr

Solution : Given: Distance = 144 km
And the time taken to row upstream = 12 hours
And the time taken to row downstream = 9 hours
So, speed of boat in upstream = $\frac{144}{12}$ = 12 km/hr
And speed of boat in downstream = $\frac{144}{9}$ = 16 km/hr
Let x be the speed of the boat in still water and y be the speed of the stream.
So, the speed of the boat in upstream = x – y
⇒ x – y = 12-----------(i)
And the speed of the boat in downstream = x + y
⇒ x + y = 16------------(ii)
Subtracting (i) from (ii), we get:
2y = 4
$\therefore$ y = 2 km/hr
Hence, the correct answer is 2 km/hr.

Correct Answer: $\frac{4}{3}$

Solution : Given: $A+B=90^{\circ}$ and $\sin A=\frac{3}{5}$
$\sin A=\frac{3}{5}=\frac{\text{Perpendicular}}{Hypotenuse}$
Let, Perpendicular = $3k$ and Hypotenuse = $5k$ --------------[where, $k$ is constant]
⇒ Base = $\sqrt{(5k)^{2}–(3k)^{2}}$
⇒ Base = $4k$
$\tan A=\frac{\text{Perpendicular}}{Base}$
⇒ $\tan A=\frac{3k}{4k}$
⇒ $\tan (90°–B)=\frac{3}{4}$
⇒ $\cot B=\frac{3}{4}$
⇒ $\tan B=\frac{4}{3}$
Hence, the correct answer is $\frac{4}{3}$.

Correct Answer: Maharashtra

Solution : The correct answer is Maharashtra.

The Ajanta and Ellora caves, situated near Aurangabad in Maharashtra, India, are ancient Buddhist architectural marvels. These sites were designated as UNESCO World Heritage Sites in 1983. The Ajanta Caves, nestled amidst the Sahyadri ranges along the Waghora River, were constructed over a span from 200 B.C. to 650 A.D.

Correct Answer: BADC

Solution : The correct choice is the first option.

The paragraph starts with sentence B, which sets the scene by describing the narrator's movement along the pavement and crossing the road, followed by sentence A, which describes the narrator's action of going up the steps to the apartment, followed by sentence D, which indicates the narrator's further action of opening the door with their key and entering, and lastly, sentence C, which provides additional information stating that the hall was empty and there was no sign of anyone having entered before the narrator.