There are 70 students in the school band. 40% of them are sixth-graders, 20% are seventh graders, and the rest are eighth-graders. How many band members are seventh-graders?

The answer to your question is 14 students

Step-by-step explanation:

Data

Total students = 70

40% sixth-graders

20% seventh graders

40% eighth graders

The Number of seventh-graders = ?

Process

1.- Use proportions and cross multiplication to solve this problem

                 70 students 100 %

                  x                    20 %

                  x = (20 x 70) / 100

                  x = 1400 / 100

                 x = 14 students are seventh-graders

                  70 students 100 %

                  x                     40%

                  x = (40 x 70) / 100

                  x = 2800 / 100

                  x = 28 students are sixth graders

Eighth-graders = 70 - 14 - 28

                         = 28

the answer is y < -3 or   y > 3

-3y > 7 + 2

-3 y > 9

y < -3