SOLUTION: The average mass of 24 boys in a class is 35.5 kg and that of 15 girls is 29kg. A new boy joins the class and his mass is 1.4kg heavier than the average mass of the whole class of

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Question 1090622: The average mass of 24 boys in a class is 35.5 kg and that of 15 girls is 29kg. A new boy joins the class and his mass is 1.4kg heavier than the average mass of the whole class of 39 people. Find the average mass of the new class of 40 people after the new boy joined the class.
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
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The average mass of 24 boys in a class is 35.5 kg and that of 15 girls is 29kg.
A new boy joins the class and his mass is 1.4kg heavier than the average mass of the whole class of 39 people.
Find the average mass of the new class of 40 people after the new boy joined the class.
:
Find the average mass of the whole class of 39 people initially
%2824%2835.5%29%2B15%2829%29%29%2F39 =
1287%2F39 = 33 kg
:
"A new boy joins the class and his mass is 1.4kg heavier than the average mass of the whole class of 39 people.
33 + 1.4 = 34.4 is the mass of the new boy
:
"Find the average mass of the new class of 40 people after the new boy joined the class
%28%281287+%2B+34.4%29%29%2F40 = 33.035 kg the average mass of the new class of 40