Answer: D) VWYZ Explanation: K+2 M+1 N-2 L,  P+2 R+1 S-2 Q,   V+1 W+2 Y+1 Z,   J+2 L+1 M-2 K  and  W+2 Y+1 Z-2 X. Except VWYZ, all the other groups follow similar pattern.

Answer: B) 26.166 minutes Explanation: Upto first 5 minutes I, J and K will fill => 5[(1/20)+(1/30)+(1/40)] = 65/120 For next 6 minutes, J and K will fill => 6[(1/30)+(1/40)] = 42/120 So tank filled upto first 11 minutes = (65/120) + (42/120) = 107/120 So remaining tank = 13/120 Now at the moment filling with C and leakage @ 1/60 per minute= (1/40) - (1/70) = 3/280.So time taken to fill remaining 13/120 tank =(13/120) /(3/280) = 91/6 minutes   Hence total time taken to completely fill the tank = 5 + 6 + 91/6 = 26.16 minutes.

Answer: B) 6 mile/hr Explanation: Let the speed of river and boat be 'r' m/min and 'b' m/min.so relative speed in upstream (b-r)m/min and in downstream (b+r)m/min.Now in upstream distnce covered in 5 min is 5(b-r)milesso total distnce covered => 1 + 5(b-r)miles in upstreamIn downstream distance covered in 5min is 5(b+r)miles Now 1 + 5(b-r) = 5(b+r)1+5b-5r = 5b+5r1 = 10rr = 1/10 mile/min => 6 mile/hr.

Answer: A) -1/2 Explanation: Rewrite equation as 122x+1 = 120   Leads to 2x + 1 = 0    Solve for x : x = -1/2