Question

The average weight of a class of students is 67.5 kg. The weight of the class teacher is 25% more than the average weight of the class. The average weight of the class is less than the class teacher by x%. The value of x is:

Answer 1

Weight of class teacher is =1.25*67.5 kg=84.375 kg;
now calculating 67.5 is how much % lessthan by 84.375 kg;
={(84.375-67.5)/84.375}*100
=20%

Answer 2

Answer:

20 %

Step-by-step explanation:

Let the y be the weight of class teacher,

Since, the average weight of the class = 67.5 kg,

According to the question,

The weight of teacher = 25 % more than the average weight of the class

⇒ y = 125 % of 67.5

⇒ y = 1.25 × 67.5 = 84.375 kg,

Thus, the weight of teacher =  84.375 kg,

The percentage that average weight of the class is less than the class teacher

$=\frac{\text{Weight of teacher - Average weight of students}}{\text{Weight of teacher}}\times 100$

$=\frac{84.375 -67.5}{84.375}\times 100$

$=\frac{1687.5}{84.375}=20\%$