There were 45 questions on the test. four points will be awarded for every correct answer, and two points will be deducted for every wrong answer. If Henry scored 150 points, how many questions did he get wrong?
Let x be the number of correct answers.
The number of wrong answers is 45 - x.
Henry's score from correct answers is 4x.
Henry's score from wrong answers is -2 * (45 - x) = -90 + 2x.
His total score is 150 points, so 4x - 90 + 2x = 150.
Combining like terms, we get 6x - 90 = 150.
Adding 90 to both sides, we get 6x = 240.
Dividing both sides by 6, we get x = <<40=40>>40.
Henry got 45 - 40 = <<45-40=5>>5 wrong answers. Answer: \boxed{5}.