Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ • π ƒ ¹ ² ³ °
 

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Re: Oral puzzles49. A rectangular area of lawn of dimesnions x and y is surrounded by a pathway of width 2 meters. What is the toal area of the pathway? Character is who you are when no one is looking. #27 20060401 01:44:20
Re: Oral puzzlesthe answer to 48 is a trick and people were supposed to say 25. well that's silly because the price would be 125 percent. then if that number was the new 100 percent and the number was 100 and is now 125 it will have to decrease by 20%. this is because 25 goes into 125 5 times and 100 devided by 5 = 20. Chaos is found in greatest abundance wherever order is being saught. It always defeats order, because it is better organized. #28 20060401 01:49:47
Re: Oral puzzles29: Chaos is found in greatest abundance wherever order is being saught. It always defeats order, because it is better organized. #29 20060401 01:50:53
Re: Oral puzzleserk. i think they get harder as you go along. Chaos is found in greatest abundance wherever order is being saught. It always defeats order, because it is better organized. #30 20060401 17:42:21
Re: Oral puzzlesNinja 101, your answer to #48 is correct! Character is who you are when no one is looking. #31 20060403 22:11:47
Re: Oral puzzlesyay! finally! something right! Chaos is found in greatest abundance wherever order is being saught. It always defeats order, because it is better organized. #32 20060404 01:13:19
Re: Oral puzzles#39 Now, let's get the length of the sides: Therefore, the answer is: #49 Let's start with the area of the path just next to the sides with lengths of and : This leaves the area of the corners. If I understand the puzzle correctly, the width of the path is measured from the edge of the lawn, to the outer edge of the path. Therefore, these 'edges' must be evenly curved, forming a of a circle with a radius of 2. And since there are 4 of these corners, the total area of the corners is: Adding these two areas, gives us the total area of the path. Let A be the area of the path: #51 The number of different outcomes of a throw is: which can also be written as (t: tales, h: heads) t  t  t t  t  h t  h  h t  h  t h  h  h h  h  t h  t  t h  t  h (obviously I wouldn't do this normally, just showing it to the ones who might not be familiar with this) This gives us 2 out of 8 posibilities where all the coins have the same face up, and they are ofc t  t  t, and h  h  h. So the answer is depending on how you want the answer :) edit: There's actually a reason for why I'm not just writing the answer. I'm showing what I'm actually doing, which might help me explain things to other people(practice makes perfect), and at the same time, people can understand how to solve the problem, if they couldn't do it themselves.(My teacher would hate me for that sentence :P grammer is prolly messed up, and it's a bit long^^) Last edited by Patrick (20060404 04:14:20) #33 20060404 14:15:05
Re: Oral puzzlesWell done, Patrick! All your answers other than #49 are correct! Character is who you are when no one is looking. #34 20060405 01:40:40
Re: Oral puzzles52. Out of three examinations with a total of 500 marks each, a student scored 45% and 55% in the first and second examinations. To have an average of 60% in all the three, how many marks should the student score in the third examination? Character is who you are when no one is looking. #35 20060405 05:18:35
Re: Oral puzzles52. since 55. you just add the two numbers before the one you want.. A classic example of series #36 20060405 14:52:23
Re: Oral puzzlesWell done, Patrick! Character is who you are when no one is looking. #39 20060406 01:19:04
Re: Oral puzzlesWell done, rm! All your answers are correct! Character is who you are when no one is looking. #40 20060406 14:21:02
Re: Oral puzzles56. The monthly income of Arthur and Richard are in the ratio 4:3 and their monthly expenses are in the ratio 3:2. If both of them save $600 a month, whats the total of their income? Character is who you are when no one is looking. #41 20060406 23:48:18
Re: Oral puzzles63. In a class, there are 18 boys who are over 160 cm tall. If these boys constitute threefourths of the boys and the total number of boys is twothird of the number of students in the class, what is the number of girls in the class? Character is who you are when no one is looking. #42 20060407 14:30:13
Re: Oral puzzles65. From the given equations, find the possible value of x+y. 66. A city has a population of 300,000 out of which 180,000 are males. 50% of the population is literate. If 70%of the males are literate, what is the number of literate females? 67. In a survey, it was found that 80% of those surveyed owned a car while 60% of those surveyed owned a mobile phone. If 55% owned botha car and a mobile phone, what percent of those surveyed owned a car or a mobile phone or both? 68. Water is filled in a container in such a manner that its volume doubles every five minutes. If it takes 30 minutes for the container to be full, in how much time would it be onefourth full? 69. In 1930, a person's age was 8 times that of his son. In 1938, the father's age became 10 times that of his son's age at 1930. What would be the age of the father and the son in 1940? Character is who you are when no one is looking. #43 20060408 15:17:54
Re: Oral puzzles70. A complete cycle of a traffic signal takes 60 seconds. During each cycle, the light is green for 25 seconds, yellow for 5 seconds and red for 30 seconds. At a randomly chosen time, what is the probability that the light will not be green? Character is who you are when no one is looking. #44 20060411 00:28:40
Re: Oral puzzles80. A car travels the first onethird of a certain distance at a speed of 10 km/hour, the next onethird at 20 km/hour and the third onethird at 60 km/hour. What is the average speed of the car for the whole journey? Character is who you are when no one is looking. #45 20060411 14:55:18
Re: Oral puzzles87. What is the value of 88. What is the value of 89. In an election, a total of 500,000 voters participated. A candidate got 255,000 votes which was 60% of the valid votes. What was the percentage of invalid votes? 90. 12 workers working 10 hours a day complete a work in 15 days. How many days would 15 workers working for 8 hours a day require to complete the same work? 91. A machine is sold at a profit of 10%. Had the machine be sold for $40 less, a loss of 10% would have been incurred. What is the cost price of the machine? 91. A sum of money deposited at compund interest becomes three times itself in 5 years. In how many years would the sum of money amount to nine times itself? 92. What is the least number by which 3675 should be multiplied so that the resultant is a perfect square? 93. What are the values of A and B if ? 94. A 40 litre mixture contains wine and water in the ratio 3:1. In order to make the ratio of wine and water 5:2, how many litres of water is to be added? 95. The length of a rectangle is 10% more than a square and its width is 10% less than the square. What is the ratio of area of the rectangle to that of the square? Character is who you are when no one is looking. #47 20060415 16:14:53
Re: Oral puzzlesExcellent, rm! All your answers other than the annswer to question 91 are correct! Character is who you are when no one is looking. #48 20060415 17:05:47
Re: Oral puzzles96. Two cars X and Y start from two places A and B respectively which are 700 kilometers apart, at 9.00 AM. Both the cars run at a speed of 60 kilometers/hour. Car X stops at 10.00 AM and starts again at 11.00 AM. At what time do the cars cross each other? Character is who you are when no one is looking. #49 20060416 16:23:52
Re: Oral puzzles101. The speed of a car increaes by 2 kilometers per hour after every hour. If the distance travelled in the first hour was 40 kilometers, what would be the total distance travelled by the car in 12 hours? 103. If A and B are positive integers such that and , then what is the value of 5A+7B? 104. Twenty times a positive integer is less than its square by 96. What is the integer? 105. Two numbers are in the ratio 4:5. When the cube of the first, square of the second and both the first and second numbers are added, the total is 630. What is the product of the two numbers? 106. The average age of the students is 23 years in a class of 75 students. The average age of the male students is 24 years and the average age of the female students is 20 years. What is the ratio of the number of male students to female students? 107. What is the value of x if ? 108. A shopkeeper gives three successive discounts of 15%, 35% and 20% respectively. What is the total resultant discount given to the customers? 109. When two dices are thrown, what is the probability that the numbers shown by both are equal? 110. A solid sphere of radius 3 cm is melted and converted into a long wire of diameter 0.2 cm. Find the length of the wire. Character is who you are when no one is looking. #50 20060417 14:43:17
Re: Oral puzzles111. A train started from a station with a certain number of passengers. At the first halt, half of the passengers alighted and 120 new passengers got into the train. At the second halt, half of the passengers alighted and then the train left for its destination with 360 passengers. How many passengers were in the train when it started from the first station? 113. A number when divided by 765 leaves a remainder 42. What would be the remainder if the number is divided by 17? 114. If an angle of a triangle remains unchanged but each of its two including sides is doubled, by what factor would the area get multiplied? 115. If m and n are natural numbers such that what is the value of m? Character is who you are when no one is looking. 