6th graders are twice the number of 7th graders; therefore, 6th graders will be 2X. The total number of students is 57.
2X + X = 57 3X = 57 X = 57 / 3 X = 19
IF X represents the 7th graders; there are 19 seventh graders present. Since 6th graders are represented by 2X; Then, 2 * 19 = 38 is the number of 6th graders present.
