The seventh and eighth grade bands held a joint concert. together there was 188 band members. if the eight grade band is 3 times as big as the seventh grade band, how big is the eight grade

Let the size of the seventh grade band be s

That means the size of the eighth grade band must be 3s because it is 3 times as big as the seventh grade band.

Combined, the two bands have 188 members.

3s and s combined is 4s. Thus 4s must equal 188.

4s = 188

s = 47

3s = 141

The eighth grade band has 141 members.

8th grade = 3x = 3 (47) = 141 band members.

7th + 8th = 188

7th = x

8th = 3x

x + 3x = 188; x = 47; 47 + 3 (47) = 47 + 141 = 188

4x = 188

4x / 4 = 188 / 4

x = 47 - - > 7th grade

8th grade = 3x = 3 (47) = 141

To check:

x + 3x = 188; x = 47;

47 + 3 (47) = 188

47 + 141 = 188

188 = 188