Hello Friends,
Today we are going to discuss some questions on Average which asked in the exams. There are many types of questions asked on Average. Here we are providing you at least one question of each type. There are at least 2 methods to solve any question but we will solve each question through tricks which consume less time, because as we know we got very less time to solve problems in the exam that's why we are telling you the short tricks, let's start....
First of all we should know what is Average? Average is the value contains by each term. Means if average of weight of 2 peoples is 40 Kg then the weight of each person will be near to 40 Kg if one person is of 41 Kg then the other will definitely of 39 Kg, Only the their average weight becomes 40 Kg. This logic is the key to solve any question on Average. So let's discuss about the questions..
Q. The average weight of a group for people was 68 Kg. When the 2 people of the group went out with 80 Kg and 84 Kg, then average weight of the group becomes 66 Kg. How many person were there in the group?
Sol. Old average = 68 Kg
New average = 66 Kg
This means the 2 persons which left the group takes 2 Kg from each person's weight, by using above logic. Assume each person of group is of 66 Kg. Now the weight of two person's which left the group is 80 Kg and 84 Kg. Means they has 26 Kg extra. So they can give 2 Kg to each person to make their weight 66 Kg and has 66 Kg of own.
So there were 26/2 = 13+2 = 15 peoples in the group.
Q. The average age of a group of students is 16 years. If a 66 year old teacher joins the group, the average increases by one year. The number of students in the group is.
Sol. Old Avg = 16 years
New Avg = 17 years
Teacher's age = 66 years. So, the teacher can distribute 1 year to each student and has 17 years of its own.
Total students = 66-17 = 49
Q. The average of group of people was calculated as 23 years. This was 2 years more than the correct average as there was an error in noting the age of 2 persons as 32 and 36 instead of 21 and 23. How many persons were there in the group?
Sol. Wrong Avg = 28 years
Correct Avg = 23 years
Wrong noted ages = 32 36
Correct ages = 21 23
11+13 = 24 years
So, 24 years are wrongly added in the total age of the group. These years increases 2 years in the age of each person. 24 years could be added in 12 peoples age to increase their age by 2 years. So, there were 12 peoples in the group.
Q. There are 30 workers working in a factory. If two of them whose salaries are Rs 950 and Rs 1120 respectively are fired and two new workers joined the factory, then the avg salary of workers is decreased by Rs 15. What is the total salary of two new workers?
Sol. Old avg = x
New avg = x-15
So old workers (leaving) takes 15 Rs from the salary of every worker + 2 new worker. So, they took 15*30 = 450 Rs extra. And there total salary is 950+1120 = 2070 Rs.Now, the total salary of new workers is 2070-450 = 1620 Rs.
That's all for today. We will provide you some questions asked in exams on Average from cricket in the next class. So continue your preparation and stay connected.
Today we are going to discuss some questions on Average which asked in the exams. There are many types of questions asked on Average. Here we are providing you at least one question of each type. There are at least 2 methods to solve any question but we will solve each question through tricks which consume less time, because as we know we got very less time to solve problems in the exam that's why we are telling you the short tricks, let's start....
First of all we should know what is Average? Average is the value contains by each term. Means if average of weight of 2 peoples is 40 Kg then the weight of each person will be near to 40 Kg if one person is of 41 Kg then the other will definitely of 39 Kg, Only the their average weight becomes 40 Kg. This logic is the key to solve any question on Average. So let's discuss about the questions..
Q. The average weight of a group for people was 68 Kg. When the 2 people of the group went out with 80 Kg and 84 Kg, then average weight of the group becomes 66 Kg. How many person were there in the group?
Sol. Old average = 68 Kg
New average = 66 Kg
This means the 2 persons which left the group takes 2 Kg from each person's weight, by using above logic. Assume each person of group is of 66 Kg. Now the weight of two person's which left the group is 80 Kg and 84 Kg. Means they has 26 Kg extra. So they can give 2 Kg to each person to make their weight 66 Kg and has 66 Kg of own.
So there were 26/2 = 13+2 = 15 peoples in the group.
Q. The average age of a group of students is 16 years. If a 66 year old teacher joins the group, the average increases by one year. The number of students in the group is.
Sol. Old Avg = 16 years
New Avg = 17 years
Teacher's age = 66 years. So, the teacher can distribute 1 year to each student and has 17 years of its own.
Total students = 66-17 = 49
Q. The average of group of people was calculated as 23 years. This was 2 years more than the correct average as there was an error in noting the age of 2 persons as 32 and 36 instead of 21 and 23. How many persons were there in the group?
Sol. Wrong Avg = 28 years
Correct Avg = 23 years
Wrong noted ages = 32 36
Correct ages = 21 23
11+13 = 24 years
So, 24 years are wrongly added in the total age of the group. These years increases 2 years in the age of each person. 24 years could be added in 12 peoples age to increase their age by 2 years. So, there were 12 peoples in the group.
Q. There are 30 workers working in a factory. If two of them whose salaries are Rs 950 and Rs 1120 respectively are fired and two new workers joined the factory, then the avg salary of workers is decreased by Rs 15. What is the total salary of two new workers?
Sol. Old avg = x
New avg = x-15
So old workers (leaving) takes 15 Rs from the salary of every worker + 2 new worker. So, they took 15*30 = 450 Rs extra. And there total salary is 950+1120 = 2070 Rs.Now, the total salary of new workers is 2070-450 = 1620 Rs.
That's all for today. We will provide you some questions asked in exams on Average from cricket in the next class. So continue your preparation and stay connected.
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