Question

Explain the Error Fifteen students in the band play clarinet. These 15 students make up 12% of the band. Your friend used the proportion 12/100 =?/15 to find the number of students in the band. Explain why your friend is incorrect and use the grid to find the correct answer

Answer 1

Explanation:

Let the total number of students in the band be x:

If 15 students make up 12% of the band, this is expressed as:

12% of x = 15

12/100 * x = 15

12x/100 = 15

12/100 = 15/x

cross multiply

12 * x = 15 * 100

12x = 1500

x = 1500/12

x = 125

Hence the total number of student in the band is 125 students

Comparing the evaluated expression 12/100 = 15/x with 12/100 =?/15 according to my friend, he used x/15 at the right hand side of the equation instead of 15/x as used in the calculation. That was where he made an error.