Answer: A) 9 Explanation: Speed in still water = Average of Speed in Upstream and speed in Downstream = 1/2 (12 + 6) kmph = 9 kmph.

Answer: B) Rs. 6000 Explanation: The wages of labourers in a factory increases in the ratio 22:25 and there was a reduction in the number of labourers in the ratio 15:11. Find the original wage bill if the present bill is Rs 5000 ?Ratio of increase of wages = 22:25Ratio of decrease of labourers = 15:11Compound ratio of wages of labourers = 22 x 15 : 25 x 11 = 330:275Final bill = Rs. 5000For 275 ratio wages = Rs. 5000For 1 ratio wages = 5000/275For 330 ratio wages = 5000/275 x 330 = Rs. 6000

Answer: B) 7.5 min Explanation: B runs around the track in 10 min.  i.e ,    Speed of B = 10 min per round  Therefore,  A beats B by 1 round   Time taken  by A to complete 4 rounds    = Time taken by B to complete 3 rounds    = 30 min    Therefore, A's speed = 30/4 min per round = 7.5 min per round  Hence, if the race is only of one round A's time over the course = 7 min 30 sec

Answer: B) 20 days Explanation: (5m + 9w)10 = (6m + 12w)8  => 50m + 90w = 48w + 96 w    => 1m = 3w 5m + 9w = 5m + 3m = 8m   8 men can do the work in 10 days. 3m +3w = 3m + 1w = 4m So, 4 men can do the work in (10 x 8)/4 = 20 days.

Answer: D) 8 hrs 15 min Explanation: A can write in 1hour = 32/6 pages Similarly, B in 1 hour = 40/5 pages Together (A+B) in 1 hour = 32/6 + 40/5 = 40/3 So, A+B write 40/3 pages in 1 hour A+B write 110 pages in (3/40) x 110 Hours = 8 hours 15 min.