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Given:

The average of three numbers = 77

First number = 2(Second number)

Second number = 2(Third number)

Formula Used:

Average = Sum of values/Number of values

Calculation:

Let the third number be x

Second number = 2x

First number = 2 × 2x = 4x

Sum of all three numbers = x + 2x + 4x = 7x

Average = 7x/3

⇒ 77 = 7x/3

⇒ 77 × 3 = 7x

⇒ 7x = 231

⇒ x = 231/7

⇒ x = 33

Third Number = x = 33

Second Number = 2x = 2 × 33 = 66 

First Number = 4x = 4 × 33 = 132

∴ The three numbers are 132, 66, 33

The correct answer is Cryogenics.

Key Points

• Cryogenics is the production of and behavior of materials at very low temperatures.
• Ultra-cold temperatures change the chemical properties of materials, which provide an interesting area of study for researchers who wish to examine the materials as they transition from gas to liquid to a solid-state.
• The temperature of any material is the measure of the energy that it contains. Rapidly moving molecules have a higher temperature than slower-moving molecules.
• Cryogenics can be used to produce cryogenic fields for rockets, in MRI machines that use liquid helium and require cryogenic cooling, storing large quantities of food, special effects fog, recycling, freezing blood and tissue samples, and even cooling superconductors.

 

Important Points

• Cytogenetics is the branch of genetics that studies the structure of DNA within the cell nucleus.
• This DNA is condensed during cell division and form chromosomes.
• The cytogenetic studies the number and morphology of chromosomes.
• In modern times we can use advanced cytogenetics techniques such as fluorescence in situ hybridization (FISH) to look at the genetic material in the cell through a light microscope but at a much higher resolution.

The correct answer is Vector.

Key Points

• Living organisms carrying the infecting agents from one person to another (human or animal) are called Vectors.
• Vectors are frequently arthropods, such as mosquitoes, ticks, flies, fleas, and lice.
• The diseases transmitted through vectors:
• Elephantiasis is transmitted by mosquitos.
• Malaria is transmitted by mosquitos.
• Rabies is transmitted by mad dogs.

 

Additional Information

• A drone is a male honey bee.
• Unlike the female worker bee, drones do not have stingers and gather neither nectar nor pollen.
• A drone's primary role is to mate with an unfertilized queen.

Given:

Cost price of sewing machine = Rs. 800

Successive discounts = 15% and 10%

Formula Used:

Equivalent discount of two successive discount = (– A) + (– B) + AB/100

Selling Price = Marked Price × (100 – discount%)/100

Calculation:

Discount = 15% and 10%

Equivalent Discount = (– 15) + (– 10) + {(– 15) (– 10)}/100

⇒ (– 15) + (– 10) + 1.50

⇒ (– 25) + 1.50

⇒ (– 23.50)

Equivalent discount = 23.50

Selling price = 800 × (100 – 23.50)/100

⇒ 800 × (76.50)/100

⇒ 800 × 0.765

⇒ 612

Selling price = Rs. 612

∴ Selling price of sewing machine is Rs. 612

According to the given information :

B is taller than A

B > A

B is not as tall as D

D > B

C is taller than E

C > E

C is shorter than A

A > C

The correct order of their heights is :

D > B > A > C > E.

D is the tallest in the batch.

Hence, the correct answer is "D".

The correct answer is Canada.

Key Points

• BRICS is the acronym coined to associate five major emerging national economies: Brazil, Russia, India, China, and South Africa.
• BRICS Tower headquarters in Shanghai.
• The first BRIC Summit took place in 2009 in the Russian Federation and focused on issues such as reform of the global financial architecture.
• South Africa was invited to join BRIC in December 2010, after which the group adopted the acronym BRICS.
• South Africa subsequently attended the Third BRICS Summit in Sanya, China, in March 2011.

Important Points

• At the Fourth BRICS Summit in New Delhi (2012) the possibility of setting up a new Development Bank was considered to mobilize resources for infrastructure and sustainable development projects in BRICS and other emerging economies, as well as in developing countries.
• The New Development Bank (NDB), formerly referred to as the BRICS Development Bank.
• President of BRICS is Marcos Prado Troyjo.

Additional Information

• The 12^th BRICS summit (21 Jul 2020 – 23 Jul 2020) was hosted by Russia.
• The 13^th BRICS summit will be hosted by India in 2021.
• India hosted two summits 4^th (2012) and 8^th (2016).

Given:

Boat takes time to cover a certain distance upstream = 8 hours 48 minutes

Boat takes time to cover the same distance downstream = 4 hours

Formula Used:

Speed = Distance/Time

Calculation:

Let speed of boat in still water be x km/h

Let speed of current be y km/h

Let the certain distance be D km

Upstream speed = (x – y) km/h

Downstream speed = (x + y) km/h

8 hours 48 minutes = 44/5 hours

D/(x + y) = 4           .....(i)

D/(x – y) = 44/5      .....(ii)

Dividing equation (i) by (ii)

\(⇒ \frac{{\frac{D}{{\left( {x + y} \right)}}}}{{\frac{D}{{\left( {x;-{\rm {y}}} \right)}}}} = ;\frac{4}{{\frac{{44}}{5}}}\)

⇒ (x – y)/(x + y) = (4 × 5)/44

⇒ 44 (x – y) = 20 (x + y)

⇒ 44x – 44y = 20x + 20y

⇒ 44x – 20x = 20y + 44y

⇒ 24x = 64y

⇒ x/y = 64/24

⇒ x/y = 8/3

⇒ x : y = 8 : 3

∴ The ratio between the speed of the boat and speed of the water current is 8 : 3

The correct answer is Sushruta.

Key Points

• Sushruta is the most celebrated physician and surgeon in India.
• He is known for his work on medicine during the Gupta period
• Though he practiced during the 5^th century, many of his contributions to medicine and surgery preceded similar discoveries in the Western world.
• Susrutha Samitha was written by Susrutha.
• He was said to have been the best surgeon during the Gupta period.
• Sushruta devotes a complete volume of his experiences to ophthalmologic diseases.
• The Gupta Dynasty ruled the mid-to-late 3^rd century (approximately) to 543 AD. Founded by Sri Gupta.

Important Points

Gupta Dynasty:

• The founder of the Gupta dynasty was Sri Gupta.
• He was succeeded by Ghatotkacha. These two were called Maharajas.
• The next ruler was Chandragupta I and he was the first to be called Maharajadhiraja.
• Chandragupta, I was succeeded by Samudragupta in about 330 A.D., who reigned for about fifty years.
• He was a great military genius and is said to have commanded a military campaign across the Deccan, and also subdued the forest tribes of the Vindhya region.
• Samudragupta's successor Chandragupta II, also known as Vikramaditya, conquered the extensive territories of Malwa, Gujarat and Kathiawar.

Key Points

Some famous events during the rule of Gupta Kings:

• The famous Chinese pilgrim, Fahien visited India during the reign of Chandragupta II.
• Out of his nine years of stay in India, he spent six years in the Gupta empire.
• Chandragupta II waged war against the Saka satraps of western India.
• Rudrasimha III, the last ruler of the Saka satrap was defeated, dethroned, and killed. His territories in western Malwa and the Kathiawar Peninsula were annexed into the Gupta Empire.
• Kumaragupta laid the foundation of Nalanda University.

The correct answer is Fathometer.

Key Points

• A fathometer is an instrument used in measuring the depth of water by the time required for a sound wave to travel from surface to bottom and for its echo to be returned.
• The fathometer dispatches sound through a submarine oscillator and receive it through a hydrophone echo receiver.

Important Points

The correct answer is 22.

Important Points

• There are 22 bones in the skull.
• Including the bones of the middle ear, the head contains 28 bones.
• 22 bones include 8 Cranial bones and 14 Facial bones.
• Cranial bones (8):
• Occipital bone
• Parietal bones (2)
• Frontal bone
• Temporal bones (2)
• Sphenoid bone (sometimes counted as facial)
• Ethmoid bone (sometimes counted as facial)
• Facial bones (14):
• Nasal bones (2)
• Maxillae (upper jaw) (2)
• Lacrimal bone (2)
• Zygomatic bone (cheekbones) (2)
• Palatine bone (2)
• Inferior nasal concha (2)
• Vomer (1)
• Mandible (1)

Additional Information

• The axial skeleton, comprising the spine, chest, and head, contains 80 bones.
• A fully grown adult features 26 bones in the spine, whereas a child can have 34.
• There are normally 26 bones in the chest.
• Ribs contain 24bones in 12 pairs.
• The appendicular skeleton, comprising the arms and legs, including the shoulder and pelvic girdles, contains 126 bones.
• There are a total of 64 bones in the arms.
• There are a total of 60 bones in the legs.
• The pelvis (or hip bone) is made up of three regions that have fused to form two coxal bones.
• They are ilium, ischium, and pubis.