Answer:
The function is linear but not a direct variation function.
Explanation:
A function is said to be of direct variation if:

where k is a fixed constant for each ordered pair (x,y) on the graph.
We are given a three points in a graph as:
(10,18) , (14,24) and (18,30)
The points seems to be in a straight line hence, the function is linear.
Also we can check the slope to check that the function is linear.
Slope of (10,18) and (14,24)

Slope of (14,24) and (18,30)

As the slope is constant.
Hence, the function is linear.
Now we will check whether it is of direct variation or not.
(10,18)

(14,24)

(18,30)

As the ratio of the y-value to x-value is not constant.
Hence, the points are not in direct variation.