ANSWER
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Ratio of 8th graders to 7th graders = 3 : 2
Let the number of graders be 3x and 2x
Number of 8th graders = 18
So , 3x = 18
x = 18/3 = 6
Number of 7th graders = 2 × 6 = 12
Ratio of 6th graders to 7th graders = 5 : 4
Let the number of graders be 5a and 4a
Number of 7th graders = 12
So , 4a = 12
a = 12/4 = 3
Number of 6th graders = 5×3 = 15 ANS
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#BE BRAINLY
Mathematics can be tricky so precise definitions are important. Without them there can be confusion which more often then not will generate a wrong answer. With clear precise definitions it is easier to understand the topic. Therefore, it is easier to get the correct answer.
You have to divide your friends weigh by 1.2 to get the result. : if you were 1.2 times taller than they, you would multiply, so the oppisite is dividing!
so it will be 64.5/1.2=53.75.
