Q: From 5 consonants and 4 vowels, how many words can be formed using 3 consonants and 2 vowels ?
Solution: From 5 consonants, 3 consonants can be selected in 5C3 ways. From 4 vowels, 2 vowels can be selected in 4C2 ways. Now with every selection, number of ways of arranging 5 letters is 5P5ways. Total number of words = 5C3*4C2*5P5 = 10x 6 x 5 x 4 x 3 x 2 x 1= 7200 The correct answer is: B) 7200
Q: Three numbers are in the ratio 4 : 5 : 6 and their average is 25. The largest number is :
Solution: Let the numbers be 4x, 5x and 6x, Then, (4x + 5x + 6x ) / 3 = 25 => 5x = 25 => x = 5. Largest number 6x = 30. The correct answer is: A) 30
Q: In a game of 100 points, A can give B 20 points and C 28 points. Then, B can give C is
Solution: The correct answer is: B) 10 points
Q: A letter lock consists of three rings each marked with six different letters. The number of distinct unsuccessful attempts to open the lock is at the most ?
Solution: Since each ring consists of six different letters, the total number of attempts possible with the three rings is = 6 x 6 x 6 = 216. Of these attempts, one of them is a successful attempt. Maximum number of unsuccessful attempts = 216 - 1 = 215. The correct answer is: A) 215
Q: if the price of a book is first decreased by 25% and then increased by 20%, then the net change in the price will be :
Solution: Let the original price be Rs. 100. New final price = 120 % of (75 % of Rs. 100) = Rs. [(120/100) * (75/100) * 100] = Rs. 90. Decrease = 10% The correct answer is: A) 10
Q: If the length of a certain rectangle is decreased by 4 cm and the width is increased by 3 cm, a square with the same area as the original rectangle would result. Find the perimeter of the original rectangle.
Solution: Let x and y be the length and breadth of the rectangle respectively.Then, x - 4 = y + 3 or x - y = 7 ----(i)Area of the rectangle =xy; Area of the square = (x - 4) (y + 3)(x - 4) (y + 3) =xy <=> 3x - 4y = 12 ----(ii)Solving (i) and (ii), we get x = 16 and y = 9.Perimeter of the rectangle = 2 (x + y) = [2 (16 + 9)] cm = 50 cm. The correct answer is: D) 50
Q: A trader sold an article at a loss of 5% but when he increased the selling price by Rs.65 he gained 3.33% on the cost price. If he sells the same article at Rs. 936, what is the profit percentage?
Solution: 103.33 CP- 0.95 CP = 65 CP = Rs. 780 profit (%) = (936 - 780)/780 x 100 = 20% The correct answer is: C) 20%
Q: A bag contains 50 tickets numbered 1,2,3,4......50 of which five are drawn at random and arranged in ascending order of magnitude.Find the probability that third drawn ticket is equal to 30.
Solution: Total number of elementary events = 50C5Given,third ticket =30 => first and second should come from tickets numbered 1 to 29 = 29C2 ways and remaining two in 20C2 ways. Therfore,favourable number of events = 29C2*20C2 Hence,required probability = 29C2*20C2/50C5 =551 / 15134 The correct answer is: A) 551/15134
Q: A sum of Rs. 725 is lent in the beginning of a year at a certain rate of interest. After 8 months, a sum of Rs. 362.50 more is lent but at the rate twice the former. At the end of the year, Rs. 33.50 is earned as interest from both the loans. What was the original rate of interest?
Solution: Let the original rate be R%. Then, new rate = (2R)%. Note: Here, original rate is for 1 year(s); the new rate is for only 4 months i.e.1/3 year(s). 725*R*1100+362.50*2R*1100*3=33.50 => (2175 + 725) R = 33.50 x 100 x 3 => (2175 + 725) R = 10050 => (2900)R = 10050 => R=100502900=3.46 Original rate = 3.46% The correct answer is: A) 3.46%
| You Have Score | /9 |