If 0.4 of a number is equal to 0.06 of another number, the ratio of the numbers is : a) 2 :3 b) 3 :4 c)3:20 d) 20 : 3 Expl : 0.4A = 0.06B -> A/B = 0.06/0.40 = 6/40 = 3/20 :. A : B = 3 : 20
It takes 10 days for digging a trench of 100 m long, 50 m broad and 10 m deep. What length of trench, 25 m broad and 15 m deep can be dug in 30 days ? a) 400 m b) 200 m c) 100 m d) 89m Expl : More days, more length (Direct) Less breadth, more length (Indirect) More depth, less length (Indirect Days 10 : 30; Breadth 25 : 50; : : 100 : x Depth 15 : 10; :. 10 * 25* 15 * x = 30 *50 * 10 *100 x= (30*50*10*100)/10*25*15 = 400 So the required length = 400m
Find the number of perfect squares in the given series 2013, 2020, 2027,................, 2300 (Hint 44^2=1936) a. 1 b. 2 c. 3 d. Can’t be determined Answer: a Explanation: The given series is an AP with common difference of 7. So the terms in the above series are in the form of 2013 + 7k. We have to find the perfect squares in this format in the given series. Given that 44^2 = 1936. Shortcut: To find the next perfect square, add 45th odd number to 44^2. So 45^2 = 1936 + (2 x 45 -1) = 2025 46^2 = 2025 + (2 x 46 - 1) = 2116 47^2 = 2116 + (2 x 47 - 1) = 2209 Now subtract 2013 from the above numbers and divide by 7. Only 2209 is in the format of 2013 + 7k. One number satisfies.
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