BEGIN BY ASSIGNING VARIABLES TO THE UNKNOWN QUANTITIES

23. Begin by assigning variables to the unknown quantities:

L = left-handed writers

R = right-handed writers

Then, write equations using the information given in the problem.

L + R = 80 and L = R + 12

Substitute the second equation into the first equation to solve for R

as follows:

L + R = 80

(R + 12) + R = 80

2R = 68

R = 34

The question asks for the number of writers who are NOT left-

handed which is the same as asking for the number of right-handed

writers (34). The correct answer is C.

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