Dear Readers, Important Average Problems for upcoming competitive Exams with Solutions. Average is an important topic from banking exam point of view. You could solve Average problems easily if you understand the basic concepts. Aspirants preparing for SBI Clerk, SBI PO, IBPS Clerk, IBPS PO, Insurance, RBI and other competitive examination can make of use these average problems. We have included some important average problems that are repeatedly asking in competitive exams. Practice lot of questions to become an expert in solving average problems and learn to use shortcuts.
Average Problems – Set 4
1). The average weight of 5 students of class II is 30 kg and the average weight of 4 students of class III is 35 kg. What is the average weight of all the 9 students?
a) 33.22 kg
b) 32 kg
c) 33.02 kg
d) Cannot be determined
e) None of these
2).There are 4 companies – 1, 2 , 3 & 4. The no. of employees working in the company are 20, 30, 25, and 15 respectively. Also the average age of employees of companies 1 , 2 , 3& 4 is 25 years, 22 years, 20 years and 27 years respectively. Find the average age of all the employees of all the four companies.
a) 22.9 years
b) 22.7 years
c) 19.8 years
d) Cannot be determined
e) None of these
3).The salary of five members of a family is Rs. 10, 000 Rs. 12, 000 , Rs. 17, 000, Rs. 15, 000& Rs. 14000. Find the average salary of all the members of the family.
a) 13500
b) 12000
c) 14000
d) 13600
e) None of these
4).The average marks of Mickey, Donald and Daisy is 60. The average marks of Donald, Daisy and Goofy is 75. If the average marks of Mickey and Goofy is 50, then the average marks obtained by Mickey is:
a) 27.5
b) 30
c) 27
d) Cannot be determined
e) None of these
5).The average of 5 numbers is 306.4. The average of the first two numbers is 431 and the average of the last two numbers is 214.5. What is the third number ?
a) 108
b) 52
c) 321
d) Cannot be determined
e) None of these
6).The sum of five numbers is 555. The average of first two numbers is 75 and the third number is 115. What is the average of last two numbers ?
a) 145
b) 290
c) 265
d) 150
e) None of these
7).Out of seven given numbers, the average of the first four numbers is 4 and that of the last four numbers is also 4. If the average of all the seven numbers is 3, fourth number is
a) 3
b) 4
c) 7
d) 11
e) None of these
8).Average weight of three boys P, T and R is 54 (1 / 3) kg while the average weight of three boys, T , F and G is 53 kg. What is the average weight of P, T, R, F and H?
a) 53.8 kg
b) 52.4 kg
c) 53.2 kg
d) Data inadequate
e) None of these
9).In a class of 52 students, the number of boys is two less than the number of girls. Average weight of the boys is 42 kg, while the average weight of all the 52 students is 40 kg. Approximately what is the average weight of the girls?
a) 41 kg
b) 39 kg
c) 40 kg
d) 38 kg
e) 42 kg
10).The average income of P, Q, R, S and T is Rs. 15000. The average income of P and Q is Rs. 12000 and the average income of R and S is Rs. 16000, Find the average income of T.
a) Rs. 20000
b) Rs. 19500
c) Rs. 19000
d) Rs. 25000
e) None of these
Answers:
1). a) 2). a) 3). d) 4). a) 5). e) 6). a) 7). d) 8). d) 9). d) 10). c)
Solution:
1).Required average weight = [ (5 × 30) + (4 × 35) ] / (5 + 4)
= (150 + 140) / 9 = 290 / 9 = 32.22 kg
Answer: a)
2).Required average
= [ (20 × 35) + (30 × 22) + (25 × 20) + (15 × 27) ] / (20 + 30 + 25 + 15)
= (500 + 660 + 500 + 405) / 90 = 22.94 years
Answer: a)
3).Let assumed mean = Rs. 14000
Deviations are – 4000, – 2000, + 3000, + 1000
Sum of deviations = – 2000
Average = (-2000) / 5 = -400
Actual average = 14000 – 400 = Rs. 13600
Answer: d)
4).Total marks of Mickey, Donald and Daisy = 3 × 60 = 180
Total marks obtained by Donald, Daisy and Goofy = 3 × 75 = 225
Hence, Goofy – Mickey = 225 – 180 = 45
Also, we are given
Total marks of Goofy and Mickey = 2 × 50 = 100
Hence, G – M = 45
G + M = 100
2 G = 145, G = 72.5 and M = 100 – 72.5 = 27.5
Answer: a)
5).According to the question,
Sum of five numbers = 5 × 306.4 = 1532
Third number = 1532 – 2 × 431 – 2 × 214.5
= 1532 – 862 – 429 = 241
Answer: e)
6).Sum of first two numbers = 75 × 2 = 150
Sum of last two numbers = 555 – 150 – 115 = 290
Average = 290 / 2 = 145
Answer: a)
7).Let the numbers be a, b, c, d, e, f and g
Then a + b + c + d = 4 × 4 = 16 …(i)
& d + e + f + g = 4 × 4 = 16 …(ii)
Also a + b + c + d + e + f + g = 3 × 7 = 21 ..(iii)
(you have to find d)
d = (i) + (ii) – (iii) = 16 + 16 – 21 = 11
Answer: d)
8).We have to determine the average weight of P, T, R, F and H
Obviously, this can’t be determined as we don’t know the weight of H.
Answer: d)
9).Let the number of boys = x and number of girls = y
Now (y – 2) = x and x + y = 52
y – 2 + y = 52
2y = 54
y = 27 , x = 25
Let the average weight of the girls be ‘a’
Then [ (25 × 42) + (27 × a)] / 52 = 40
Or 27 × a = (52 × 40) – (25 × 42)
Or, 27 × a = 2080 – 1050
a = 1030 / 27 = 38.148 = 38 kg
Answer: d)
10).Sum of the incomes of P, Q, R, S and T = 15000 × 5 = 75000
Sum of income of P& Q = 2 × 12000 = 24000
Sum of income of R& S = 2 × 16000 = 32000
Average income of T = (P + Q + R + S + T) – (P + Q) – (R + S)
= 75000 – 24000 – 32000 = Rs. 19000
Answer :c)