Each student can score a maximum of 15 points on the 6.B exam. This year, the average score, rounded to the nearest tenth, was 10.4. After the test, Honzik realized that he had read one question wrong. He could have scored 4 more points and the average number of points rounded to the nearest tenth would have increased to 10.6. Determine how many least and most children were in class 6B this year.
#Middle school please help
silk grotto
sharp hawkBOT
Each student can score a maximum of 15 points on the 6.B exam. This year, the av...
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viscid lotus
so 10.35 rounds to 10.4
the biggest gap you can have is 10.35 to (just under) 10.65
@silk grotto
silk grotto
Yeah?
Well i got this so far
Wait
let's call x the average before rounding and n the number of people
then 10.35 < x < 10.45
but also 10.55 < x+4/n < 10.65
so 4/n is between 0.1 and 0.3
since 4/n > 0.1
40 > n
and since 4/n < 0.3
40/3 < n so n >= 14
That means n has to be the same or smaller than 40
And bigger than 13
silk grotto
So all numbers from 14 to 40 should worl