What is the angle above the x axis (i. e., "north of east") for a vector with components (15 m, 8 m)?

If you draw out the two components in a head-to-nose fashion, you will create a right angle triangle something like the picture, that is if I interpreted the information right (the way I interpreted it is 15m east and 8m north);
The dotted line represents the x-axis;
Θ represents the desired angle;
Using trigonometry, we can create and solve an equation to get the angle (Θ);
In this case, you can use use sin or cos, I'll go with sin:
SinΘ = opp/hyp
SinΘ = 8/15
Θ = Sin⁻¹(8/15)
= 32.23 ⇒ 32.2°

Well if you have 20 bats you probably want 20 balls? you don’t have enough context to answer the question.