Aptitude - Average - Discussion

His mother's view is that his weight cannot be greater than 68 kg
but she cant said that >=68
so the solution is 66+67/2=133/2=66.5
answer is none of these..

I got ans like tis way..., may i dont know whether is it correct r nt
view of arun avg=(65+72)/2=68.5
view of his brothers avg=(60+70)/2=65
view of his mother taken as=68
Therefore the avg of above three as=(68.5+65+68)/3=67

Arun says that his age is > 65 but < 72
Therefore his age in between 66 to 71.

View of his brother, Arun's age is >60 but < 70,
Therefore Arun's age in between 61 to 69.

View of his mother, Arun's age is Cannot be > 68,
That means Arun's age under 68 years only.


The above three members opinions Arun's age in in between 66 years to 68 years,

Then (66+67+68)/3.

65 - 72 -(1) : 68.5.

60 - 70 -(2) : 65.0.

68 -(3) : 68.0.
-------
201.5/3 = 67.

Logic Concept:

Let Arun age is X.
In Arun's opinion: 65 > X < 72.
Possibilities: 66, 67, 68, 69, 70, 71.

In Brother's opinion: 60 > X < 70.
Possibilities: 61, 62, 63, 64, 65, 66, 67, 68, 69

In Mother's opinion: X <= 68.
Possibilities: 1, 2, 3......61, 62, 63, 64, 65, 66, 67, 68.

Now check what similar terms are matching in every 3-possibilities i.e 66, 67, 68.

To find Average age = (66+67+68)/3.

Note: 3 = Three possible values. It is not Arun+Brother+Mother at all.

((65+72)+(60+70)+(68))/5 = 67.

The average age of man and son is 40 years. The ratio of their ages is 11:5 respectively. What is the son's age ? Solve it.

@Anwi.

40/0.5 = 80 man = 80*11/16 = 55 and son's age = 80-55 = 25.

Whether the answer & method is right or wrong explain anyone?

Why aren't we assuming fractional values?

In The Given Problem, they said that Arun assume that his age will be more than 65 and less than 70,
A--> 65<A<75.

His brother's, 60< A < 70.
His Mom's opinion is, A<=68.

So the common numbers by the above three conditions are 66, 67, 68
by(66+67+68)/3 = 201/3 = 67kg.