143. Mr. joe's family consists of six people, himself, his wife
and their four children. It is known that the average age
of the family immediately after the birth of the first,
second, third and fourth child was 16, 15, 16 and 15
years respectively. Find the age of Mr. Joe's eldest son
বয়সের গড়
8
) 8 years
if the present average age of the entire family is 16 years.
(6 সদস্যের মি. জো এর পরিবার- সে নিজে, তার স্ত্রী এবং তাদের 4
জন সন্তান। ঐ পরিবারের গড় বয়স প্রথম, দ্বিতীয়, তৃতীয় ও চতুর্থ সন্তান
জন্মের সময় যথাক্রমে 16, 15, 16 এবং 15। যদি মি. জো পরিবারের
গড় বয়স 16 বছর হয়। তবে মি, জো এর বড় সন্তানের বয়স কত?)
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b 12 years © 15 years d) 16 years
ধান : ধরি, মি. জো এর বয়স x; তার স্ত্রীর বয়স y
প্রথম সন্তানের বয়স z; দ্বিতীয় সন্তানের বয়স A
তৃতীয় সন্তানের বয়স B; চতুর্থ সন্তানের বয়স C
জা, স্ত্রী এবং প্রথম সন্তানের বয়সের গড় = 16
ত, x + y + z = (16 x 3)
Answers
Answer:
b 12 years
Step-by-step explanation:
When the first child was born, the total age of all the family members
= (16 × 3) years
= 48 years
When the second child was born, the total age of all the family members
= (15 × 4) years
= 60 years
By the time the second child was born, each one of the 3 family members had grown by
=(60−483)=123
= 4 years
Hence, the age of eldest son when the second child was born = 4 years
When the third child was born, the total age of all the family members
= (16 × 5) years
= 80 years
By the time, the third child was born, each one of the four family members had grown by
= (80−604)
= 5 years
So, the age of the eldest son when the third child was born
= (4 + 5) years
= 9 years
When the fourth child was born, the total age of all the family members
= (15 × 6) years
= 90 years
By the time, the fourth child was born, each of the five family members had grown by
= (90−805)
= 2 years
So, the age of the eldest son when the fourth child was born
= (9 + 2) years
= 11 years
At present, the total age of all the 6 family members
= (16 × 6) years
= 96 years
By now, each one of the 6 members have grown by
= (96−906)
years
= 1 year
Hence, the present age of the eldest son
= (11 + 1) years
= 12 years
The question States when the first kid was born, the family's combined age was equal to
16 x 3, or 48 years.
When the second kid was born, the family's combined age was 60 years
15 x 4 years.
Each of the three family members had increased in size by
=60-48/3
=12/3
=4 years by the time the second kid was born.
Consequently, the oldest boy was 4 years old when the second kid was born.
When the third kid was born, the family's combined age was 16 x 5 years, or 80 years.
Each of the four family members had grown by 80-60/4
=20/4
= 5 years by the time the third kid was born.
Consequently, the oldest son's age when the third kid was born
= 9 years
= 4 + 5 years
When the fourth kid was born, the family's combined age was 90 years 15 x 6 years.
Each of the five family members had grown by
90-80/5
=10/5
= 2 years by the time the fourth kid was born.
Therefore, the oldest son's age at the birth of the fourth kid was 9 + 2 years, or 11 years.
The six family members' combined age at this time is 96 years (16 x 6).
Each of the six individuals has now grown by the equivalent of one year =96-90/6
=6/6
=1 year
Consequently, the oldest son is currently 11 + 1 years old.
which concludes he was 12 years old.
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