A record number of city public high school students are taking and passing Advanced Placement exams giving them a potential head start on earning credits toward a college degree. Moreover, the largest gains are among black and Hispanic students:

At this Queens high school, the Advanced Placement English class was reading Virginia Wolf when Mayor Bill de Blasio dropped in.

"When I was in high school, I had to read this book too," he said. "And I found it challenging. Okay? Who finds this book, like, a tough thing to make sense of, raise your hand? All right then you're all better than me."

Advanced Placement, or AP courses are supposed to challenge students with college-level work.

Students who do well in the AP exams at the end of the courses often can receive credits toward their college degree in return.

On Tuesday de Blasio and his schools chancellor announced that more city students are taking AP courses and passing the tests — a goal of the mayor's.

"This year, we have 63 high schools that have new AP courses," Mayor de Blasio said. "31 of them never had a single AP course before."

De Blasio has pledged that within five years, every public high school will offer at least five AP courses.

Now only a third of schools are meeting the goal, and 140 of the city's 500 high schools don't offer any AP courses at all.

Black and Hispanic students are much more likely to attend schools without the high-level classes.

"Talk about Tale of Two Cities, this is one of the starkest examples," the mayor said.

Actually, the number of students taking AP courses and passing the tests has been rising for more than a decade.

Both rates increased about 8 percent last year — and 120 percent since 2006, when the city began tracking students' performance on the exams.

Black students notched the biggest gains last year — the number of black students taking the test jumped 14 percent — the number passing them climbed 18 percent.

Still, the majority of students taking and passing the exams are white and Asian, even though black and Hispanic students make up most of the student population. The Mayor says he hopes to change that.