GED Mathematical Reasoning TestQuantitative Problem Solving with Rational NumbersEasy
A farmer harvested 5/8 of his cornfield on Monday. On Tuesday, he harvested an additional 1/4 of the cornfield. What fraction of the cornfield is still unharvested?
- A1/2
- B3/8
- C1/8
- D7/8
Show answer & explanationAnswer & explanation
Correct answer: C. 1/8
First, find the total fraction harvested by adding 5/8 and 1/4 (which is 2/8). This gives 7/8 harvested. Then, subtract this from the whole field (1) to find the unharvested portion: 1 - 7/8 = 1/8.
Why the other options are wrong
- A. This is an incorrect simplification or calculation error.
- B. This is an incorrect calculation of the remaining fraction, possibly by subtracting 1/4 from 5/8.
- D. This is the total fraction of the cornfield that has been harvested, not what is unharvested.
Subtracting Fractions from a Whole
To find a remaining fractional part after some parts have been removed, first sum the parts removed, and then subtract this sum from the whole, represented as 1.
- A whole is represented as 1 (or n/n).
- Fractions must have a common denominator for addition/subtraction.
- The remaining fraction is 1 - (sum of removed fractions).
Memory trick: The whole pie minus eaten slices equals what's left.