A student who didn’t study for the upcoming quiz decides to ‘wing it’ and just guess on the 10 question quiz. Every question has 4 choices (a – d).

A student who didn’t study for the upcoming quiz decides to ‘wing it’ and just guess on the 10 question quiz. Every question has 4 choices (a – d). What is the pobability that his grade on the quiz will be at most 50%?