There are two surgical technicians responsible for cleaning and maintaining the sterility of the surgical instruments utilized during surgery. Prior to lunch, one surgical technician cleaned $\frac { 1 } { 4 }$ of the instruments and the other cleaned $\frac { 1 } { 3 }$ of the instruments. How much of the cleaning remains?
A) $\frac { 5 } { 12 }$ of the instruments remain to be cleaned
B) $\frac { 6 } { 13 }$ of the instruments remain to be cleaned.
C) $\frac { 5 } { 3 }$ of the instruments remain to be cleaned.
D) $\frac { 7 } { 14 }$ of the instruments remain to be cleaned
E) $\frac { 5 } { 13 }$ of the instruments remain to be cleaned

Question

Quizplus · Accepted Answer

To find the remaining portion of the instruments to be cleaned, add the fractions of the instruments cleaned by each technician and subtract from 1 (the whole). The first technician cleaned $\frac{1}{4}$ and the second cleaned $\frac{1}{3}$. Adding these gives $\frac{1}{4} + \frac{1}{3} = \frac{3}{12} + \frac{4}{12} = \frac{7}{12}$. Subtracting this from 1 gives $1 - \frac{7}{12} = \frac{5}{12}$, which means $\frac{5}{12}$ of the instruments remain to be cleaned.

There Are Two Surgical Technicians Responsible for Cleaning and Maintaining 14\frac { 1 } { 4 }41​

There Are Two Surgical Technicians Responsible for Cleaning and Maintaining $\frac { 1 } { 4 }$