Aptitude - Average - Discussion

Discussion Forum : Average - General Questions (Q.No. 7)
7.
The average monthly income of P and Q is Rs. 5050. The average monthly income of Q and R is Rs. 6250 and the average monthly income of P and R is Rs. 5200. The monthly income of P is:
3500
4000
4050
5000
Answer: Option
Explanation:

Let P, Q and R represent their respective monthly incomes. Then, we have:

P + Q = (5050 x 2) = 10100 .... (i)

Q + R = (6250 x 2) = 12500 .... (ii)

P + R = (5200 x 2) = 10400 .... (iii)

Adding (i), (ii) and (iii), we get:  2(P + Q + R) = 33000  or   P + Q + R = 16500 .... (iv)

Subtracting (ii) from (iv), we get P = 4000.

P's monthly income = Rs. 4000.

Discussion:
93 comments Page 3 of 10.

Kayalvizhi said:   9 years ago
p + Q = 5050
Q + R = 6250
P + R = 5200

(P + Q) - (Q + R) = 1200.

Now 5200 - 1200 = 4000.

I done like this is correct way or not?

Kalpana said:   8 years ago
Anyone can help me by solving this?

The average of a group of 13 members is 48 years. A member of the group age 57 retired and in place of him a new person aged 18 joined the group. Find the new average of the group.

Amani said:   9 years ago
Easily explained @Yesu Babu.

Aman Dewangan said:   9 years ago
It can be solved directly:

(p+q) = (2*5050).....(1)
(p+r) = (2*5200).....(2)

We want to get value of p.

So,

Add eq (1 & 2)

=> 2p+(q+r) = 20500....(3)
=> As (q+r) = (2*6250) is given,

Put this in eq.(3).

2p = 20500-12500,
2p = 8000,
p = 4000.

Vipin said:   9 years ago
The quickest method is :

(p and q) + (p and r) - (q and r).
5050 + 52000 - 6250.
10250 - 6250.

Answer is = 4000.

Pranav said:   9 years ago
Think Logically.

Given Data:

P and Q = 5050.
Q and R = 6250.
P and R = 5200.

Solution:

Take common point = (Q and R) - (P and R).
(6250) - (5200) = 1050 -----> equation 1.

Now,
(P and Q) - (equation 1).
(5050) - (1050) = 4000.

So, the Answer is 4000.

Bhanu ravali said:   1 decade ago
P + Q + = 10100.

+ Q + R = 12500.

---------------

P + 2Q + R = 22600.

P + + R = 10400 (subtraction).

--------------

2Q = 12200.

Q = 6100.

P + Q = 10100.

P = 10100 - 6100.

= 4000.

Nidhi said:   1 decade ago
Thanks @Vinay.

Now I got it you have done the simplest way to solve.

You have a good explain ability.

Swapnil Andhale said:   6 years ago
Avg = sum/Number.

sum = avg*Number.

ie P+Q = 5050*2.
(2 is a no.of employees, candidate, etc . only P & Q is there ie. multiply it by 2).

Kiran said:   1 decade ago
P & Q = 5050.
Q & R = 6250.
P & R = 5200.

= 5050/2 + 6250/2 + 5200/2.
= 2525+3125+2600.
= 8250-6250.
= 4000/-.


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