Answer: A) Solid carbon dioxide Explanation:   Dry ice is solid form of carbon dioxide, used as a cooling agent.   It lower temperature than that of water ice and not leave any residue.

Answer: C) C Explanation: It is explicitly given that all the 4 black balls are different, all the 3 red balls are different and all the 5 blue balls are different. Hence this is a case where all are distinct objects.   Initially let's find out the number of ways in which we can select the black balls. Note that at least 1 black ball must be included in each selection.   Hence, we can select 1 black ball from 4 black ballsor 2 black balls from 4 black balls.or 3 black balls from 4 black balls.or 4 black balls from 4 black balls.   Hence, number of ways in which we can select the black balls   = 4C1 + 4C2 + 4C3 + 4C4= 24-1 ........(A)   Now let's find out the number of ways in which we can select the red balls. Note that at least 1 red ball must be included in each selection.   Hence, we can select 1 red ball from 3 red ballsor 2 red balls from 3 red ballsor 3 red balls from 3 red balls   Hence, number of ways in which we can select the red balls= 3C1 + 3C2 + 3C3=23-1........(B)   Hence, we can select 0 blue ball from 5 blue balls (i.e, do not select any blue ball. In this case, only black and red balls will be there)or 1 blue ball from 5 blue ballsor 2 blue balls from 5 blue ballsor 3 blue balls from 5 blue ballsor 4 blue balls from 5 blue ballsor 5 blue balls from 5 blue balls.   Hence, number of ways in which we can select the blue balls= 5C0 + 5C1 + 5C2 + … + 5C5= 25..............(C)   From (A), (B) and (C), required number of ways=  2524-123-1

Answer: B) 41325 Explanation: The given series follows a pattern of +19, x19, +17, x17, +15, x15,... Here the number which is to be replaced in ? is 41310+15=41325.

Answer: D) 3/10 Explanation: One hour = 60 min 18/60 = 3/10

Answer: C) 10 Explanation: Let the price of each note book be Rs.x. Let the number of note books which can be brought for Rs.300 each at a price of Rs.x be y. Hence xy = 300 => y = 300/x (x + 5)(y - 10) = 300 => xy + 5y - 10x - 50 = xy =>5(300/x) - 10x - 50 = 0 => -150+x2+5x multiplying both sides by -1/10x => x2+15x-10x-150=0 => x(x + 15) - 10(x + 15) = 0 => x = 10 or -15 As x>0, x = 10.

Answer: C) 18 yrs Explanation: Let Siya's age = x Then Riya's age = 4x But given Riya's age = 24 => 4x = 24 => x = 6 Hence Siya's age = 6 yrs => The age difference = 24 - 6 = 18 yrs.

Answer: C) capillary action phenomenon Explanation: The absorption of ink by blotting paper involves capillary action phenomenon because the blotting paper is a thin and a smooth paper which allows a little thicker liquids like ink to absorb.

Answer: C) Both (A) and (B) follows Explanation: