Re: There are at least three times as many boys as (average)
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06 Jan 2021, 01:12
[quote="Carcass"]There are at least three times as many boys as girls in a class. On a test, the boys’ average score is 78, and the girls’ average score is 94. Which of the following could be the average test score for the entire class?
Indicate all such values.
A. 88
B. 86
C. 84
D. 82
E. 80
For every 3 boys there is 1 girl. That implies for every 75 boys there are 25 girls. This totals to 100 students so that we can compare with 100%.
Sum of boy's marks + Sum of girl's marks --> 78x75 + 94x25 = 8200.
Average of entire class --> 8200/100 = 82.
The question says there are at least 3 boys for every girl. So, the ratio of boys to girls can increase to 4 to 1 or even more, in this case number of boys will increase and the average of the entire class will decrease because boys' average is 78, which is less than girls.
So, the best answers will be 82 and 80.