Question

write the next 3 terms of AP whose first term is 11 and the common difference is 1.5

Answer 1

Hope this answer will help

Answer 2

Here 11 is the first term and 1.5 is the common difference 
which means that you need to add 1.5 to the previous number
The AP will be 11,12.5,14
11, 11+1.5, 11+1.5+1.5