Answer: A) Rs. 316 Explanation: S.I. for 2 years = (514 - 415) = Rs. 99S.I. for 1 year = 99/2 Principal = (415 - 99) = Rs. 316.

Answer: B) 338 Explanation: We know that 40% = 25   40% of 265 + 35% of 180 = 50% ?   25 x 265 + 35% of 180 = 50% ?   We know that (35% of 180 = 180% of 35) & 180% = 95   25 x 265 + 95 x 35 = 50% ?   106 + 63 = 50% ?   ?= 2 x 169 = 338.

Answer: A) 12 days Explanation: It is given that efficiency ratio =3:1 so time ratio will be 1:3 (since work is same)   Also given that time diff = 32 days. ratio difference = 3-1 =2  2 ratio = 32 days 1 ratio = 16 days. So A will alone finish it in 16 days and B will finish it in 16*3 = 48 days.   Total work = LCM of 16 and 48 = 48. Total time = Total work/Total efficiency  ie; 48/4= 12 days.

Answer: D) 144 Explanation: Given ratio of pens and pencils = 3 :2 Number of Pens = 3x Number of Pencils = 2x Average number of pencils & Pens = 3x + 2x2 = 180 5x = 360 => x = 72 Hence, the number of pencils = 2x = 72 x 2 = 144.

Answer: C) 22.54% Explanation: C.P. of 50 kg rice = Rs. (36 x 20 + 14 x 36) = Rs. (720 + 504) = Rs.1224.   S.P. of 56 kg rice = Rs. (50 x 30) = Rs.1500. Profit = 1500 - 1224 = Rs.276    Profit % = ProfitC.P×100  = 2761224×100 = 22.54%.

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

Answer: B) (1+2m)/2 Explanation: log4928 = 12log77×4   = 12+122log72= 12+log72= 12 + m= 1+2m2.