Question 1

If the total sales for a business in a certain year were ₹ 132000. What were the sales in june, if june sales were half the monthly average?

Accepted Answer

Monthly sale = yearly sale / 2 = 132000 / 2 = ₹ 11000 June's sale = monthly sale / 2 = 11000 / 2 = ₹ 1000

Question 2

The average monthly income of a person in a certain family of 5 members is ₹ 1000. What will be monthly average income of a person in the same family, if the income of one person increased by ₹ 12000 per year?

Accepted Answer

Total Income of the family per month = 5 x 1000 = ₹ 5000 Increased amount per month = 12000/12 = ₹ 1000 Now, total amount of family income = ₹ 6000 per month So, the average income of the family per month after increase = 6000/5 = ₹ 1200

Question 3

The average temperature of the first three days of the week is 25° C and that of the next three days is 27° C If the average ofthe whole week is 26.5° C, then the temperature of the last week of the week is

Accepted Answer

Let the temperature on the last day of the week be x° C Average of the week = ( 3 x 25 + 3 x 27 + x ) / 7 = 26.5 ⇒ 3 x 25 + 3 x 27 + x = 7 x 26.5 ⇒ 156+ x = 185.5 ∴ x = 29.5 So, the temprature on the last day of the week is 29.5° C

Question 4

Five years ago, the average age of four men was 48 yr. Now, a new man joins and the average age increases by 2 yr. What is the age of the new man?

Accepted Answer

Sum of the ages of 4 men five years ago = 48 x 4 =192 yr And sum of present ages of the four men = 192 + 5 x 4 = 212 yr Now ( 212 + Age of the new man ) / 5 = 50 ∴ Age of the new man = 50 x 5 - 212 = 38 yr.

Question 5

Average of a,b and c is 11, average of c,d and e is 17 average of e and f is 22 and the average of e and c is 17 . Find out the average of a, b, c, d, e and f.

Accepted Answer

a + b + c = 11 x 3 = 33 .....(i) c + d + e = 17 x 3 = 51 .....(ii) e + f = 22 x 2 = 44 .....(iii) e + c = 17 x 2 = 34 .....(iv) From Eqs. (ii) and (iv), we get 34 + d = 51 ∴ d = 17 Now adding Eqs. (i), (ii), (v), we get a + b + c + d + e + f = 33 + 44 + 17 = 94 ∴ Average of a, b, c, d, e and f = 94/6 = 152⁄3

Question 6

Mumbai gets wheat from different regions. If it gets 1200 kg from Nasik at the rate of ₹ 30 per kg, 1500 kg from Ratnagiri at the rate of ₹ 25 per kg and 2000 kg from Kolhapur at the rate of ₹ 32 per kg, find the average cost of wheat procured by Mu…

Accepted Answer

Average cost =( w1x1 + w2x2 + w3x3 ) / (w1 +w2 +w3) = ( 1200 x 30 +1500 x 25 + 2000 x 32) / ( 1200 + 1500 + 2000 ) = 137500 / 4700 = ₹ 29.25 per kg

Question 7

The average age of three boys is 15 years.if their ages are in the ratio 3: 5: 7, the age of the youngest boys is?

Accepted Answer

Age of A : age of B : age of C = 3 : 5 : 7 So the average age of 3 boys (3x + 5x + 7x ) /3 = 15 ⇒15x= 15 x 3 ∴ x= 3

Question 8

The average of odd number upto 100 is?

Accepted Answer

sum of odd number upto 100 = 1 + 3 + 5 + 7+....+ 95 + 97 + 99 =(1+99) + (3+97) + (5+95) +.... upto 25 terms = 100 + 100 + 100 +.... upto 25 terms = 2500 Average = 2500 /50 = 50

Question 9

On a journey across Delhi, a taxi average 30 kmph for 60% of the distance, 20 kmph for 20% of it and 10 kmph for the remainder, the average speed for the whole journey is?

Accepted Answer

Let total journey = y km Total time taken = time taken during 60% of distance + time taken during 20% of distance + time taken in remaining distance = [( 60y / 100 ) / 30] + [( 20y / 100 ) / 20] + [( 20y / 100 ) / 10] = ( y / 50 + y / 100 + y / 50 )hrs = y/20 hours. Average speed = total distance traveled / total time taken. = [y / ( y/20 )] km/hr =20 km/hr.

Question 10

With an average speed of 40km/hr. a train reached its destination in time. If it goes whith an average speed of 35km/hr, it is late by 15 minute . The total journey is?

Accepted Answer

Let total journey be y km. From question y/35 - y/40= 15/60 ⇒ y = ( 35 x 40 )/ ( 4 x 5 ) = 70 ∴ Total Journey = 70 km

Question 11

The average of 10 number is calculate as 15. It is discovered later on that while calculating the average one number , namely 36 was wrongly read as 26. The correct average is?

Accepted Answer

New sum of numbers = previous sum - 26 + 36 =10 x 15 - 26 + 36 = 160 ∴ Correct Average = 160 / 10 = 16.

Question 12

The average of 13 result is 68. The average of first seven is 63 and that of the last seven is 70 , the seventh result is?

Accepted Answer

Seventh Result = sum of first 7 results + sum of last 7 results - sum of all 13 results. ⇒ Seventh Result = (7 x 63) + (7 x 70) - (13 x 68 ) =47

Question 13

The average of 25 results is 18, that of first twelve is 14 and of last twelve is 17 . Thirteenth result is?

Accepted Answer

Thirteenth Result = sum of all 25 results - sum of first 12 results - sum of last 12 results. = 25 x 18 - 12 x 14 – 12 x 17 =78

Question 14

The average temperature of Monday, Tuesday, Wednesday, and Thursday was 38° C and that of Tuesday, Wednesday, Thursday and Friday was 40° C, if the temperature on Monday was 30° C, the temperature of Friday was?

Accepted Answer

From question M + T + W + TH = 4 x 38° = 152° ⇒ T + W + TH =152° – 30° = 122° Again from question ⇒ T + W + TH + F = 4 x 40° = 160° ⇒ F = 160° – 122° = 38°

Question 15

The average of 5 consecutive number is n , if the next two number are also include, the average of 7 number will?

Accepted Answer

Sum of 5 consecutive integers x + ( x +1 ) + ( x +2 ) + ( x + 3 ) + ( x +4 ) = 5n ⇒ 5x + 10 = 5n ⇒ x = ( n – 2 ) ......(i) Average of 7 consecutive integers = [( 5x + 10 ) + ( x + 5 ) + ( x + 6 )] / 7 = 7x + 21 / 7 = x + 3 .....(ii) from eq. (i) and (ii) New average = x + 3 = ( n – 2 + 3 ) = n + 1 So , the new average increases by 1 .

Question 16

A man whose bowling average is 12.4 takes 5 wicket for 26 runs and thereby decreases his average by 0.4. The number of wickets taken by him, before his last match is?

Accepted Answer

Let the number of wickets taken before the last match = y Bowler's overall average = total run scored / total wicket taken by bowler Then, (12.4y + 26 ) / (y + 5) = 12 ∴ x = 85

Question 17

There were 35 students in a hostel. If the number of students increased by 7, the expenses of the mess were increase by Rs 42 per Day , while the average expenditure per head diminished by Re. 1 The original expenditure of the mess was?

Accepted Answer

Let the original expenditure be Rs. y per day , Then, y / 35 - [( y + 42 ) / 42 ] = 1 ⇒ 42y - 35 ( y + 42 ) = 35 x 42 ∴ 7y = 35 x 42 + 35 x 42 ⇒ y = ( 2 x 35 x 42 ) / 7 = 420 Hence , the original expenditure is Rs . 420

Question 18

The average age of a husband and a wife was 23 year when they were married 5 year ago. The average age of the husband, the wife and child, who was born during the interval is 20 years now . How old is the child now?

Accepted Answer

Age of child = sum of age of husband , wife and child - sum of age of husband and wife. = [(20 x 3) - (23 x 2 + 5 x 2)] years = 4 years.

Question 19

Ten years ago the average age of a family of 4 members was 24 years. Two children having been born average age of the family is same today. What is the present age of the youngest child if they differ in age by 2 years?

Accepted Answer

Let the age of youngest child be y. Then y + ( y + 2 ) = ( 24 x 6 ) - ( 24 x 4 + 4 x 10) = 144 - 136 ⇒ 2y + 2 = 8 ∴ y =3 years

Question 20

The mean temperature of Monday to Wednesday was 37° C and of Tuesday to Thursday was 34° C . If in the temperature on Thursday was 4/5 th that of Monday, what was temperature on Thursday?

Accepted Answer

M + T + W = 3 x 37 = 111° C .....(1) T + W + Th = 3 x 34 = 102 ° C ......(ii) Let M = y Then, Th = 4y/5 subtraction (ii) from (i) we get, M - Th = 9° C ⇒ y - 4y / 5 = 9° C ⇒ y = 45° C ∴ Temperature on thursday = (4 x 45) / 5° C = 36° C

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