How many student wear spectacles?

12

Step-by-step explanation:

This is a rather simple one is it not? We know that there are 40 students in the class and 30% wear spectacles. Your current answer (30/40) is wrong unfortunatly because it assumes that it is 30% of 100 as a percent is percentage of 100 (eg. 30% is 30/100).

Expression: 30%*40.

Converting the percent to a decimal (30/100), we get 0.3.

Then simple multiplication, 0.3*40 which is 12.

the answer is n