- The average marks of Rahul in 10 papers is 80. If the highest and the lowest scores are not considered, the average is 81. If his highest score is 92, find the lowest?
(a) 55
(b) 60
(c) 62
(d) Cannot be determined
(e) None of these
Explanation:
Total marks of 10 papers = 80 x 10 = 800
Total marks of 8 papers = 81 x 8 = 648
Total marks of two papers = (800 – 648) = 152
If highest total is 92, then the lowest total is
(152 – 92) = 60.
- The average daily wages of A, B and C is Rs 120. If B earns Rs 40 more than C per day and, A earns double of what C earns per day, the wages of A per day are?
(a) Rs 80
(b) Rs 120
(c) Rs 160
(d) Rs 100
(e) None of these
Explanation:
Let daily wages of C = X
Then, daily wages of A = 2X
and daily wages of B = X + 40
Hence, average daily wages of A, B and C
= (X + 2X + X + 40) / 3 = (4X + 40)/3
Thus, (4X + 40)/3 =120
=>4X + 40 = 360
=>4X = 320
X = 80.
Therefore, Wages of A per day = 2 x 80 = Rs 160.
3. The average of five consecutive odd numbers is 61. What is the difference between the highest and lowest numbers?
(a) 4
(b) 8
(c) 12
(d) 16
(e) None of these
Explanation:
Let the numbers be x, x + 2, x + 4, x + 6 and x + 8.
Then [x + (x + 2) + (x + 4) + (x + 6) + (x + 8) ] / 5 = 61.
or 5x + 20 = 305 or x = 57.
So, required difference = (57 + 8) – 57 = 8
4. Biswajit was asked to find the arithmetic mean of the numbers 3, 11, 7, 9, 15, 13, 8, 19, 17, 21, 14 and x. He found the mean to be 12. What should be the number in place of x ?
(a) 6
(b) 7
(c) 8
(d) 9
(e) None of these
Explanation:
Clearly, we have (3 + 11 + 7 + 9 + 15 + 13 + 8 + 19 + 17 + 21 + 14 + x) / 12 = 12.
or 137 + x = 144 or x = 144 – 137 = 7.
5. The average salary of 90 employees in an organization is Rs.14,500 per month. If the no. of executives is twice the no. of clerks, then find the average salary of clerks?
(a) 11,500
(b) 12000
(c) 13200
(d) can’t be determined
(e) None of these
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 answer.
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- The average salary of 120 employees in a bank is Rs.15,000 per month. If the no. of Assistants is thrice the no of POs and the average salary of Assistants is 1/3rd of the average salary of Pos, then find the average salary of POs ?
(a) 18,000
(b) 25,000
(c) 36,000
(d) 30,000
(e) None of these
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
- The average value of the properties of Akhil, Munna and Anil is Rs.130cr. The Property of Akhil is Rs. 20cr greater than the property value of Munna and Anil’s property value is Rs. 50cr greater than the Akhil’s property value. The value of Anil’s property is
(a) Rs. 120cr
(b) Rs. 170cr
(c) Rs. 100cr
(d) Rs. 150 cr
(e) None of these
Explanation:
Property value of Munna x
130*3 = x+x+20+x+20+50
390 = 3x+90
3x=300
X=100
Anil = 100+20+50 = 170
- The average monthly expenditure of a family was Rs. 2,200 during the first 3 months; Rs. 2,250 during the next 4 months and Rs. 3,120 during the last 5 months of a year. If the total savings during the year were Rs. 1,260, then the average monthly income was:
(a) Rs. 2,605
(b) Rs. 2,805
(c) Rs. 2,705
(d) Rs. 2,905
(e) Rs. 2,995
Explanation:
Total expenditure for the year
= [2200 × 3 + 2250 × 4 + 3120 × 5]
= 6600 + 9000 + 15600 = Rs. 31200
Total saving = Rs. 1260
Total income = expenses + savings = 31200 + 1260 = Rs. 32460
Average income = 32460/12 = Rs. 2705
- The average marks of 100 students were found to be 40. Later on it was discovered that a score of 53 was misread as 83. Find the correct average corresponding to the correct score.
(a) 38.7
(b) 39
(c) 39.7
(d) 41
(e) None of these
Explanation:
Average of 100 students = 40
Total = 40 × 100 = 4000
Error = 83 – 53 = 30 (high)
So correct average = 3970/100 = 39.7
- In a one-day cricket match, Agarkar, Sehwag, Sachin, Dravid and Ganguly scored an average of 39 runs. Dravid scored 7 more than Ganguly. Ganguly scored 9 fewer than Agarkar. Sehwag scored as many as Dravid and Ganguly combined; and Sehwag and Sachin scored 110 runs between them. How many runs did Sachin score?
(a) 47
(6)51
(c) 53
(d) 49
(e) None of the above
Explanation:
- Having scored 98 runs in the 19th innings, a cricketer increases his average score by 4. What will be his average score after the 19th innings?
(a) 28
(b) 26
(c) 24
(d) 22
(e) None of these
Explanation:
- A Mathematics teacher tabulated the marks secured by 35 students of 8th class. The average of their marks was 72. If the marks secured by Reema were written as 36 instead of 86, then find the correct average marks up to two decimal places.
(a) 73.41
(b) 74.3
(c) 72.43
(d) 73.43
(e) None of these
Explanation:
- The mean of five observations is 4 and their variance is 5.2. If three of these observations are 1, 2 and 6, then the other two are
(a) 2 and 9
(b) 3 and 8
(c) 4 and 7
(d) 5 and 6
(e) None of these
Explanation:
- If p, q, r be three positive numbers such that p > q > r. When the smallest number is added to the difference of the other two numbers, then the average of the resultant number and the original numbers except the smallest number is 21 more than the average of all the three original numbers. The value of (p- q) is
(a) 7
(b) 14
(c) 63
(d) 42
(e) None of these
Explanation:
- The average age of A and B is 20 years. If C were to replace A, the average would be 19 and if C were to replace B, the average would be 21. The ages of A, B and C are (in years)
(a) 22, 17,16
(b) 22, 18, 20
(c) 30, 18, 15
(d) 23, 17 ,15
Explanation:
A + B = 2 x 20 ——(1)
C + B = 2 x 19 ———(2)
A + C = 2 x 21 ——–(3)
Now,
By adding equation (1), (2) and (3) we get,
A + B + C = 60 ———(4)
Subtracting equation (4) to equation (1) we get,
C = 20
Therefore,
B = 18
A = 22