He needs to answer 6 mails.
Step-by-step explanation:
Given,
The number of mails = 18
Among them, he needs to answer 30% of mail.
To find the number of mails he needs to answer.
Formula
Of represents multiplication
Now,
The number of mails he needs to answer = 30% of 18
= 30% × 18
= [tex]\frac{30}{100}[/tex] × 18
= 5.4
So,
He needs to answer 6 mails.