Answer:
28
Step-by-step explanation:
18+6+4=28
We want to find one-half of the reciprocal of 7/sqrt(98). Let's write down an expression for this:

We can rewrite 98 into 


The square root of 49 is 7



This should be your answer. Let me know if you need any clarifications, thanks!
2,400
20% of 3,000= 600
3,000 - 600= 2,400