#### Data Interpretation

• ( 1 ) The average salary of the entire staff in a office is Rs 120 per month. The average salary of officers is Rs 460 and that of non officer is Rs 110. If the number of officer is 15, then find the number of non-officer in the office?

• 1) 480
• 2) 500
• 3) 510
• 4) 540
• Discussion in forum
Solution : Let the required number of non-officers = a
Then, 110a + 460 * 15 = 120 (15 + a)
or, 120a - 110a = 460 * 15 - 120 * 15 = 15 (460 -120)
or, 10a = 15 * 340; a = 15 * 34 = 510

discussion

• ( 2 ) The average age of husband, wife and their child 3 years ago was 27 years and that of wife and the child 5 years ago was 20 years. The present age of the husband is

• 1) 40
• 2) 35
• 3) 45
• 4) 55
• Discussion in forum
Solution : Sum of the present ages of husband, wife and child = (27 * 3 + 3 * 3) years = 90 years.
Sum of the present ages of wife and child = (20 * 2 + 5 * 2) years = 50 years.
Husband's present age = (90 - 50) years = 40 years

discussion

• ( 3 ) A student's mark was wrongly entered as 83 instead of 63. Due to that the average marks for the class got increased by half 1/2. What is the number of students in the class?

• 1) 45
• 2) 40
• 3) 35
• 4) 30
• Discussion in forum
Solution : Let the total number of students = x
The average marks increased by 1/2 due to an increase of 83 - 63 = 20 marks.
But total increase in the marks = (1/2)*x = x/2
Hence we can write as x/2=20 => x = 20*2 = 40

discussion

• ( 4 ) Ram obtained 76, 65, 82, 67 and 85 marks (out of 100) in history, civics, geography, hindi and english. What are his average marks?

• 1) 65
• 2) 69
• 3) 75
• 4) NONE
• Discussion in forum
Solution : Average = (76 + 65 + 82 + 67 + 85)/5 = 375/5 = 75
Hence average = 75

discussion

• ( 5 ) The average of Devendra marks in 7 subjects is 75. His average in six subjects excluding Science is 72. How many marks did he get in Science?

• 1) 72
• 2) 93
• 3) 90
• 4) 100
• Discussion in forum
Solution : Marks in Science (7*75 - 6 *72) = 93.

discussion

• ( 6 ) A cricketer has completed 10 innings and his average is 21.5 runs. How many runs must he make in his next innings so as to raise his average to 24?

• 1) 42
• 2) 45
• 3) 47
• 4) 49
• Discussion in forum
Solution : Total of 10 innings = 21.5 * 10 = 215
Suppose he needs a score of a in 11th innings; then average in 11 innings = (215 + a)/11 = 24 or, a = 264-215 = 49

discussion

• ( 7 ) A library has an average of 510 visitors on Sundays and 240 on other day. The average number of visitors in a month of 30 days starting with sunday is

• 1) 280
• 2) 285
• 3) 290
• 4) 295
• Discussion in forum
Solution : As the month begin with sunday, so there will be five sundays in the month. So result will be: = (510 * 5 + 240 * 25)/30 = 8550/30 = 285

discussion

• ( 8 ) In Meena's opinion, his weight is greater than 65 kg but less than 72 kg. His brother does not agree with Meena and he thinks that Meena's weight is greater than 60 kg but less than 70 kg. His mother's view is that his weight cannot be greater than 68 kg. If all are them are correct in their estimation, what is the average of different probable weights of Meena?

• 1) 70kg
• 2) 69kg
• 3) 61kg
• 4) 67kg
• Discussion in forum
Solution : Let Meena's weight = x. Then
According to Meena, 65 < x < 72 ------------(equation 1)
According to brother, 60 < x < 70 ------------(equation 2)
According to mother, x ≤ 68 ------------(equation 3)
Given that equation 1,equation 2 and equation 3 are correct. By combining these equations,
we can write as
65 < x ≤ 68
That is x = 66 or 67 or 68
average of different probable weights of Meena = (66 + 67 + 68)/3 = 67

discussion

• ( 9 ) Nine persons went to a hotel for taking their meals. Eight of them spent Rs.12 each on their meals and the ninth spent Rs.8 more than the average expenditure of all the nine. What was the total money spent by them.

• 1) 115
• 2) 116
• 3) 117
• 4) 118
• Discussion in forum
Solution : Let the average expenditure of all the nine be RS.x
Then, 12 * 8 + (x + 8) = 9x
Therefore x = 13
Total money spent = 9x = RS.(9 * 13) = Rs.117

discussion

• ( 10 ) There were 42 students in a hostel. If the number of students increases by 7, the expenses of the mess increases by Rs 49 per day.While the average expenditure per head diminishes by Rs. 1. Find the original expenditure of the mess.

• 1) 588
• 2) 388
• 3) 456
• 4) 688
• Discussion in forum
Solution : Let the average expenditure was Rs. x
So total expenditure will be 42x.
When 7 more students join the mess, total expenditure = 42x + 49
Average expenditure = (42x + 49)/(42+7) = (42x + 49)/49 = x - 1
=> 42x + 49 = 49x -49
=> 49 + 49 = 49x - 42x
So x= 14, therefore original expenditure of the mess= 42*14=Rs 588

discussion