Once you attempt the question then PrepInsta explanation will be displayed.

Step-by-step explanation:

Average age of a family of 4 members was 19 years, 4 years back.

Let the ages of 4 members be a,b,c,d 4 years ago

19 =sum of all ages/4

19 = a+b+c+d/4

19 *4 = a+b+c+d

76 = a+b+c+d

So, the sum of ages of 4 members 4 years ago is 76

Now after four years their ages will be increase by 4

So, the sum of ages of 4 members after 4 years = a+4+b+4+c+4+d+4

=a+b+c+d+16

= 76+16

= 92

Let the present age of baby be x

Sum of ages of 4 members and baby = 92+x

Now total members = 4+1=5

the average age of the family same even today.

So, 19 = (92+x)/5

19 * 5 =92+x

95 =92+x

x=3

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