A pupil copied down a sum incorrectly using ⅕+2/6 instead of ⅘+⅙, what is the difference between the correct and incorrect answers?
To find the difference between the correct and incorrect answers, we need to calculate the correct answer first.
The correct sum is ⅘ + ⅙. To add these fractions, we need to find a common denominator. The common denominator of 5 and 6 is 30.
So, ⅘ can be rewritten as 6/30 and ⅙ can be rewritten as 5/30.
Adding these fractions together gives us (6/30) + (5/30) = 11/30.
Now let's calculate the incorrect answer the pupil wrote down, which is ⅕ + 2/6.
Again, we need to find a common denominator to add these fractions. The common denominator of 5 and 6 is 30.
⅕ can be rewritten as 6/30 and 2/6 can be simplified to 10/30.
Adding these fractions together gives us (6/30) + (10/30) = 16/30.
Now, to find the difference between the correct and incorrect answers, we subtract the incorrect answer from the correct answer:
Correct answer - Incorrect answer = (11/30) - (16/30)
To subtract these fractions, they must have the same denominator, which they already do.
So, subtracting the numerators, we have 11 - 16 = -5.
The difference between the correct and incorrect answers is -5/30.
Therefore, the difference is -5/30 or -1/6 or -0.1667.