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The average weight of 40 students in a class is 75 kg. By mistake the weights of two students are read as 74 kg and 66 kg respectively instead of 66 kg and 54 kg. Find the corrected average weight of the class
Answer – b) 74.50 kg Explanation : Weight of 40 students = 40*75 new weight = 40*75 – 74 – 66 + 66 + 54 = 40*75 – 20 so new average =( 40*75 – 20)/40 = 74.50 kg
The average weight of 40 balls is 5 grams. When the weight of the basket is added to the weight of balls, the average increased by 0.5 grams. Find the weight of the basket.
Answer – c) 25.5 gm Explanation : (40*5 + B)/41 = 5.5 (B is the weight of basket)
There are 50 students in a hostel. Now the number of students got increased by 8. Due to this the expenses of the mess increased by 30 rupees per day while the average expenditure is decreased by 2 rupees. Find the original expenditure.
Answer – b) 912.5 rupees Explanation : Let initial expenditure is E per day. Now it is increased by 30 rupees per day, Initial students = 50 and now they are 58, E/50 – (E + 30)/58 = 2
Solve for E, We will get E = 912.5 rupee.
The average age of the class is 15 years. The average age of boys and girls is 13 and 16 years respectively. If the number of girls in the class is 18 then find the number of boys in the class.
Answer – c) 9 Explanation : B*13 + 18*16 = 15*(18 + B)
A cricketer has an average of 55 after playing 20 innings. How much runs should he scores in the next inning so as to increase the average to 57.
Answer – c) 97 Explanation : Runs after 20 innings = 55*20, so (1100 + X)/21 = 57, after solving we will get X = 97
The average marks obtained by 100 candidates in an examination are 45. If the average marks of the passed students are 50 while the average marks of the failed students is 40. Then find the number of students who passed the examination.
Answer – c) 50 Explanation : Let P = passed students and failed students = F. So 45*100 = 50*P + 40*F and P + F = 100. Solve for F and P, we will get P = 50.
The average age of 30 students is 16 years. If the age of the teacher is also included then the average age increased by 1 year, find the age of the teacher.
Answer – c) 47 year Explanation : Teacher age is T years. So, 30*16 + T = 31*17
The present average age of a family of 5 members is 40 years. If the youngest member of the family is 12 years old, then find the average age of the family at the time of birth of the youngest member.
Answer – d) 35 Explanation : Present age of the family = 5*40 = 200 years. 12 years ago at the time of the birth of youngest member, age of family = 200 – 12*5 = 140.
So average age = 140/4 = 35 year
The average age of a husband and wife at the time of marriage is 22 years.After 3 years, they have a one year old child. Find the average age of the family of three at the time of birth of the child.
Answer – c) 16 years Explanation : At the time of marriage sum of the age of husband and wife = 44 years.
After three years, total age of the family = 44 + 3+ 3+ 1 = 51 years.
At the time of child birth, age of family = 51 111 = 48 years.
So average age = 48/3 = 16 years
In a certain year the average monthly salary of a person is 5000 rupees. If for the first 7 months the average salary is 5300 and for the last 6 months, the average salary is 4600 rupees. Find the income of the person in 7th month.
Answer – b) 4700 Explanation : Let the income of seventh month is A, then 12*5000 = 5300*7 + 5300*6 – A
The average salary of 90 employees in an organization is Rs.14.500 per month.
If the no of executive is twice the no of clerks, then find the average salary of clerk ?
Answer – 4.Can’t be determined Explanation : 90 => 2:1=> 60:30
Total Salary = 60*salary of executive +30 * salary of clerk 90*14500 = 60*x+30*y X, y not given so we can’t determine
The average value of property of Agil, Mugilan and Anitha is Rs.130cr.The Property of Agil is 20cr greater than the property value of Mugilan and Anitha property value is 50cr greater than the Agil property value. The value of property of Anitha is
Answer – 2.170cr Explanation : Property value of Mugilan x 130*3 = x+x+20+x+20+50 390 = 3x+90 3x=300 X=100
Anitha = 100+20+50 = 170
If the average marks of 1/5 of class is 70% and 2/5 class is 45% and the average mark of remaining class is 60%, then the average % of the whole class is
Answer – 4.56 Explanation : Avg = 100*[x/5 *70/100 + 2x/5 * 45/100 +2x/5*60/100 ] /x = 70+90+20/5
=56
The average price of 100 mobiles in an electronic shop is Rs.27,000. If the highest and lowest mobiles are sold out then the remaining 98 mobiles average price is 26,400.The cost of lowest mobile is Rs.18,000.Find the cost of highest mobile price
Answer – 2.94800 Explanation : 100*27000 – 98*26400 = 27,00,000 – 25,87,200 = 1,12,800
The cost of highest mobile price = 1,12,800 18,000 = 94800
There are 10 compartments in passenger train carries on average 15 passengers per compartment. If atleast 15 passengers were sitting in each compartment, no any compartment has equal no of passengers , and any compartment does not exceed the number of average passengers except 10th compartment.Find how many passengers can be accommodated in 10 compartment ?
Answer – 2.51 Explanation : No of passengers = 15*10 = 150 15+14+13+12+11+10+9+8+7 = 99
150 99 = 51
There are five times the number of two wheelers as there are three wheelers.The no of four wheelers are equal to the number of two wheelers. Find the average number of wheel per vehicle ?
Answer – 4.3 Explanation : No of 3 wheeler = x, no of wheels = 3x No of 2 wheeler = 5x, no of wheels = 10x No of 4 wheeler =5x, no of wheels = 20x Avg = 3x+10x+20x/x+5x+5x = 33x/11x = 3
In a particular week the average number of people visited the museum is 70. If we exclude the holidays then the average number is increased by 28. Further if we exclude the day which the maximum of 210 visitors visited the museum, then the average become 40.Find the no of holidays in the week
Answer – 4.Two Explanation : Total no of visitors in a week = 70* 7 = 490 X = no of holidays Exclude hloidays (7x)*98 =490 7x = 5 X = 2
Arjun gets 62 marks out of 100 in English, 81 out of 120 in Chemistry and 75 out of 150 in maths. The average marks of Arjun(in %) in all the three subjects is
Answer – 1.60% Explanation : 62/100 = 62%
81/120 = 67.5%
75/150 = 50%
Avg = 62+67.5+50/3 = 179.5/3 = 59.8 = 60%
The average salary of 120 employees in the bank is Rs.15,000 per month. If the no of assistant is thrice the no of POs and average salary of assistant is 1/3 of the average salary of POs then find the average salary of POs ?
Answer – 4.30,000 Explanation : 120 = 1:3 =30:90 = PO : Assistant 120*15000 = 30*x+ 90 *x/3 18,00,000 = 90x+90x/ 3 54,00,000*3 = 180x X = 30000
In a class of 60 students 23 are girls. The average mark of boys is 45 and average mark of girls is 52. What is the average mark of the class?
Answer – 3.47.7 Explanation : 60 students => 23 G and 37 B Average = 23*52 + 37*45/ 60 = 2965/60 = 47.7
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