Question

in a class 20% of the students wear spectacles .if 28 students calculate calculate the number of students in the class​

Answer 1

Answer:

% of students not wearing spectacles = 100% – 20% = 80%

no. of students = x

therefore ,

$\frac{80}{100} \times x = 28 \\ 80x = 2800 \\ x = \frac{2800}{80} \\ x = 35$

therefore , total no. of students = 35 + 28 = 63

Answer 2

$\huge \sf\underline \red{Answer : }$

$\: \: \: \: \: \: \: \: \: \: \: \: \sf \underline \orange{ Total\: students\: in \: class \: is \: 35}$

$\: \: \: \: \: \: \: \: \: \: \: \: \sf \underline \pink{students \:wear \: glasss \: is \: 35 - 28 = 7}$

$\huge \sf \underline \pink{Given : }$

• Total percent of students wear glasses is 20 %

• Total number of students who do not wear glasses = 28

$\sf \underline{let \: the \: \%\: of \: total \: students \: be \: 100}$

$\sf \underline{the \: \% \: of \: students \: who \: do \: not \: wear \: glasses}$

$\sf{ = (100 - 20)\%}$

$\sf { = 80\%}$

$\: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \sf \underline{let \: the \: total \: students \: be \: x}$

$\: \: \: \: \: \: \: \: \: \: \: \: \: \: \sf{ \implies \: 80\%of \: x = 28}$

$\: \: \: \: \: \: \: \: \: \: \: \: \: \: \sf{ \implies \: 0.8= 28}$

$\: \: \: \: \: \: \: \: \: \: \: \: \: \: \sf{ \implies \: x = \dfrac{28}{0.8} }$

$\: \: \: \: \: \: \: \: \: \: \: \: \: \: \sf{ \implies \: 35}$

$\sf \underline{so}$

$\: \: \: \: \: \: \: \: \: \: \: \: \sf \underline \pink{total \: students\: in \: class \: is \: 35}$

$\: \: \: \: \: \: \: \: \: \: \: \: \sf \underline \pink{students \:wear \: glasss \: is \: 35 - 28 = 7}$