The unit of ratio is expressed as none. Ratio comprises of similar type of quantities so the units cancel out each other and thus there is no unit for a ratio. There is no unit for ratio. The numbers in the ratio will be of same unit - the unit can be meter or gram or litre or any such unit.
The answer and work is shown by the picture given.
Answer: 0,2 or 20%
Step-by-step explanation:
A. 38
Let X = seventh graders
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.
Add both numbers to check: 19 + 38 = 57.
