SAT Math Question for the week of 08/08/2021

John scored 88, 92, 96, and 96 in the first four chemistry tests of the school year. If all the tests are out of 100 and are equally weighted, what is the mean score of the four chemistry tests?

Maps to Category 57 of the book.

---

Answer posted on 08/15/2021: Answer is 93.

mean = sum of numbers/count of numbers.

sum of numbers = 88 + 92 + 96 + 96 = 372.

count of numbers = 4.

mean = 372/4 = 93

SAT Math Question for the week of 08/01/2021

The equation of a line m in the xy-plane is y = 2x + 5. Which of the following is also an equation of the line m?

A) 2x - 2y = 5

B) 2x + 2y = 5

C) 6x - 3y = -15

D) 6x + 3y = -10

Maps to Category 2 of the book.

---

Answer posted on 08/08/2021: Correct answer choice is C.

The slope of line m from the given equation is 2.

Since the answer choices are given in the standard form, determine the answer choice where -A/B = 2.

Calculation is not required. For the slope to be positive, either A or B must be negative. This eliminates answer choices B and D. Since in answer choice A both A and B are 2, the slope is -2/-2 = 1. This eliminates answer choice A.

SAT Math Question for the week of 07/25/2021

A truck delivered n number of boxes weighing 20 pounds and t number of boxes weighing 30 pounds to a warehouse. The equation w = 20n + 30t can be used to determine the total weight w, in pounds, of the boxes. If the total weight of the boxes delivered was 480 pounds and 12 boxes weighed 30 pounds, how many boxes weighed 20 pounds?

Maps to Category 15 of the book.

---

Answer posted on 08/01/2021: Answer is 6.

w = total weight of boxes is given as 480.

t = number of 30 pound boxes is given as 12.

Plug the above values in the equation to determine the number of 20 pound boxes = n.

w = 20n + 30t --> 480 = 20n + (30 x 12) --> 480 = 20n + 360 --> 20n = 120 --> n = 6