Where is the entire question?
Answer:

Step-by-step explanation:

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
=
× 18
= 5.4
So,
He needs to answer 6 mails.
Answer:
2 2/11 hours
Step-by-step explanation:
Let the number of hours
Jack spent programming his app = J
Chris spent programming his app = C
Total hours if they worked together = T
Hence,
1/T = 1/3 + 1/8
Lowest Common Denominator = 34
1/T = 8 + 3/24
1/T = 11/24
Cross Multiply
T × 11 = 1 × 24
T = 24/11
T = 2 2/11 hours
Therefore, it would take them to program 2 2/11 hours to program the same app working together