Question

Choose the inequality that describes the following problem.

Mark wants to get at least a 90% for his marks in his science class. So far, he has
taken five 100-points tests, and he scored 460 points total. The final test is 150
points. What must he score to finish the class at his goal of at least 90%?

Answer 1

`x\geq 125`

Explanation:

• So first we have to find out the total number of points possible
• So he took 5 tests each with a max score of 100 points, so that's 500 points total
• The final test will be 150 points, so his whole grade is out of 500+150= 650 points
• He has already scored 460 of those 650 points
• Now how much must he get in the least, on the last test in order to make 90%?
• Now we need to find what 90% of 650 points is
• so
  `(90)/(100) *650=(90*650)/(100) =585points`
• Then we ask ourselves, how much must we add to 460, to get 585 points? 585-460= 125 points
• So Mark needs to get either 125 points or more on the next test to make 90% or more
• Now let's say the letter
  `x` means whatever grade number Mark gets on his next test
• This number must not be less than 125, so it must be either equal to or greater than 125 points
• So
  `x\geq 125`