Answer: B) 8 Explanation:     AmitBharatNo.of Days4540Efficiency2.22Percent(=145)2.5 Percent(=140)   Amit did the work in 56 days = 56×145×2=2845    Therefore, Rest work 17/45 was done by Amit and Bharath = 174517360 = 8 days       ( since Amit and Bharath  do the work in one day = 145+140=17360)

Answer: B) 17 Explanation: Total student= 39, boys : girls = 2:1, hence no of boys= 2/3(39)= 26num of girls= 1/3(39) = 13 , since radhika ranked 15 among 39 student from topand ranked 8 among girls from bottom , this means 7 girls are below radhika, rest 13-9= 5 girls are above her, now from 14 toper 5 are girls hence 14-5=9 boys.Hence num of boys below radhika are 26-9=17

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

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

Answer: B) Rs. 420 Explanation: As given in the question, Marked price is 25% more than the Cost price. => C.P of the article = 34 x 400 = 300  Now,  Let the original S.P of the article be Rs. P Now the new S.P = P + 16.666 +13.333300 x P  => S.P = 7P6 According to the question, 7P6 - 300 = 2P - 300 => 5P = 1800 => P = Rs. 360 Hence, the increased S.P = 360 x 7/6 = Rs. 420.