The average weight of a class increases by 1 kg, when
A joins the class� Later when B also joins, the average
weight further increases by 1/2 kg� If the number of
students now in the class is 14, the difference in the
weights of A and B ______�
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0
Answer:
okay!!!!!!! may be 2/1 think
Answered by
0
Answer:
the weight difference is 5kg
Let the weight of A be a kg and that of B be b kg.After A and B join, total number of students in the class is 14.
∴ Before A and B joined, the strength of the class was 12. If we assume that the average weight of the 12 students is n, then after A joins, it is 1213na+
1213na+ = n + 1,⇒ 12n + a = 13n + 13 –––– (1)
⇒ a = n + 13 After B joined, the average increases by 1/2.
∴ 1214112nabn++=++,⇒ 12n + a + b = 14n + 14 + 7 –––– (2) (2) – (1) gives b = n + 8 and a = n + 13∴ a – b = 5. Ans: 5
Step-by-step explanation:
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