Pre Algebra Math Mate?

S

swimfree

New member
On a 6 question quiz, a correct answer is awarded 3 points and an error or no attempt is -2. Zac received 8 points for the quiz. how many questions did he answer correctly?

At noon, Trevor and Kim start running from the same point. Trevor runs east at a speed of 5mph and Kim runs west at a speed of 3 mph. At what time will they be 12 miles apart?

What are the next two numbers in this sequence?
486,162,54,18,______,_________

Thank you in advance and if you can only answer a few it is okay!
<3
 
Let x = correct answer and y = incorrect answer

x + y = 6 (1)

3x - 2y = 8 (2)

2 x (1) gives 2x + 2y =12 (3)

(2) + (3) gives 5x = 20 , x = 4

Sub. x =4 into (1) 4 + y = 6 , so y= 2

4 answers were answered correctly.


Let x = distance Trevor is from the starting point = 5t miles ( d = vt = 5t)
Let y = distance Kim is from the starting point = 3t miles ( d =vt = 3t)


x + y = 12

5t + 3t = 12

8t = 12

t = 12/8 = 1.5 hours

After 1hour and 30 minutes are 12 miles apart.

486 , 162 , 54 , 18 , 6, 2
 
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