Trevor needs a 93 on his second quiz to have a quiz average of 90. What score did Trevor receive on his first quiz?

2 Answers
May 16, 2018

Answer:

87

Explanation:

The average of his score can be given by: #(93+"his first quiz mark")/2=90#

#93+"his first quiz mark"=90times2#

#93+"his first quiz mark"=180#

#"his first quiz mark"=180-93=87#

May 16, 2018

To find the average... we always have to add all the numbers and divide it by the number of the numbers

For example....

Find the average of #5,9,123#

Add 'em up

#137#

Three number added this up... so divide this number by 3 to find average

#137/3=45.bar666#

Here... #45.bar666# is the average of the three numbers

Back to the question

Let... the first quiz points be #x#

Then total would be #93+x#

Two numbers would give the average #90# so....

#(93+x)/2=90#

#93+x=180#

#color(blue)(x=87#