Let the required number be 'X' Condition 1 :   XX = 2X  => 2X2 = X => X = 12   Condition 2 : X × X = X2=> X = 12   Therefore, 12 is the number which becomes double when it is divided by itself and becomes half when it is multiplied by itself.

Answer: A) 60 Explanation: Given letters are k, l, m, n, o = 5 number of letters to be in the words = 3 Total number of words that can be formed from these 5 letters taken 3 at a time without repetation of letters = 5P3 ways. ⇒ 5P3 = 5 x 4 x 3 = 60 words.

Answer: A) Rs. 3550 Explanation: Let the cost price of the article be 'P' Then from given data, P + 28P100 = 4544=> 128P = 454400=> P = 3550 Hence, the cost price of the article = P = Rs. 3550

Answer: A) 5 Explanation: The following arrangements satisfy all 3 conditions. Arrangement 1: 3 books in a row; 12 rows. Arrangement 2: 4 books in a row; 9 rows.Arrangement 3: 6 books in a row; 6 rows.Arrangement 4: 9 books in a row; 4 rows.Arrangement 5: 12 books in a row; 3 rows.   Therefore, the possible arrangements are 5.

Answer: A) 400 m Explanation: Speed = 78 x 5/18 = 65/3 m/sec.Time = 1 min = 60 sec.Let the length of the train be x meters.Then, (900 + x)/60 = 65/3x = 400 m.

Answer: B) 24 kmph Explanation: Average speed=total distance/total timeLet distance to store be  Kthen, total time =(K/20)+(K/30)=K/12and, total time =(2K)so average speed= 2K / (K/12) = 24kmph.

There are approximately 6 trillion miles in a light-year, so the distance we need to go is 6 trillion miles / light-year times. 4 light-years is equal to 24 trillion miles. So, this whole would take 1.2 billion hours. There are 24 hours a day and 365.25 days per year, so this time in years is 137 thousand years.

Answer: C) Rs. 7000 Explanation: Let the sum be Rs. S.(S x 18 x 2)/100 - (S x 12 x 2)/100 = 840 => 36S/100 - 24S/100 = 840 => 12S/100 = 840 => S = 7000.