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Tanmay27101994
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Average age of the students in a class of 50 is 13. The weights of eac 14 Sep 2020, 02:33
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70% (01:44) correct 30% (02:19) wrong based on 10 sessions

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Average age of the students in a class of 50
is 13. The weights of each is directly
proportional to the height and the height is
also found to be in direct proportion to the
age. A student of age 11 is 165 cm tall, with
weight being 33 kg. Find the average weight
of the class.
a. 33 kg
b. 39 kg
c. 36 kg
d. 30 kg
e. 32 kg

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B
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Average age of the students in a class of 50 is 13. The weights of eac 14 Sep 2020, 04:34
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Weight = k*Age, where k is constant

33= k*11
k=3

Avg Wt. of class = 3*13 = 39


Tanmay27101994
Average age of the students in a class of 50
is 13. The weights of each is directly
proportional to the height and the height is
also found to be in direct proportion to the
age. A student of age 11 is 165 cm tall, with
weight being 33 kg. Find the average weight
of the class.
a. 33 kg
b. 39 kg
c. 36 kg
d. 30 kg
e. 32 kg
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SaurbahThakur
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Average age of the students in a class of 50 is 13. The weights of eac 14 Sep 2020, 04:40
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All the attributes are in proportion and as given in question the average age is 13, only option b is the multiple of 13 hence the answer

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Average age of the students in a class of 50 is 13. The weights of eac 14 Sep 2020, 10:35
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Given: Average age of the students in a class of 50 is 13. The weights of each is directly proportional to the height and the height is also found to be in direct proportion to the age. A student of age 11 is 165 cm tall, with weight being 33 kg.
Asked: Find the average weight of the class.

Weight = k1 * Height = k2 * Age
33 = k1 * 165 = k2 * 11
k1 = 33/165 = 3/15 = 1/5
k2 = 3

Average weight = k1 * Average weight = k2 * Average Age
Average weight = k2 * 13 = 3*13 = 39

IMO B
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Average age of the students in a class of 50 is 13. The weights of eac 14 Sep 2020, 11:17
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given that
avg age of students 13 ( class of 50)---(1)
and weight = a* height also
weight = b*age
we can say
33= a*165 ; a= 1/5 and
33= b*11 ; b = 3
from 1 we can say that
weight = b* avg age ; 3*13 ; 39
OPTION B

Tanmay27101994
Average age of the students in a class of 50
is 13. The weights of each is directly
proportional to the height and the height is
also found to be in direct proportion to the
age. A student of age 11 is 165 cm tall, with
weight being 33 kg. Find the average weight
of the class.
a. 33 kg
b. 39 kg
c. 36 kg
d. 30 kg
e. 32 kg
Show more

Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Problem Solving (PS) Forum
Still interested in this question? Check out the "Best Topics" block above for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!
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