The digit that 3, 71 _ divisible by 9 is 4 and 7
i think the answer might be 3
7 * 0.5 + 3 * 0.8 = 3.5 + 2.4 = 5.9
<span>5.9/10 X 100 = 59%
</span><span>59% concentration of new mixture</span>
Answer:
There are 1240 students at Washington middle school.
Step-by-step explanation:
Percentages and Portions
We can find portions of a whole by correctly managing the percentages of each part. We know 25% of all students at Washington middle school were on the honor roll. From that portion, 60% of the students are seventh graders. That means 40% of the 25% are eight graders, i.e. 40*25%=10% were from eight grade.
We have 10% of all students are 124, thus the number of students are 124/10%=1240
There are 1240 students at Washington middle school.
Let's test the answer. 25% of 1240 students are on the honor roll, which is 310 students. 40% of 310 students are from 8th grade, 40%*310 = 124 as stated in the problem
The awnser is the simplified stystem is the arbitrary solution of the original system of equations
