What is 18 1/5 + 1 3/5 - 2 1/5 - 10

*
12 2/5
17 2/5
-10 1/5
7 3/5

1 answer

To solve the expression \(18 \frac{1}{5} + 1 \frac{3}{5} - 2 \frac{1}{5} - 10\), we will first convert all mixed numbers into improper fractions, then perform the arithmetic.

  1. Convert the mixed numbers to improper fractions:

    \[ 18 \frac{1}{5} = \frac{18 \times 5 + 1}{5} = \frac{90 + 1}{5} = \frac{91}{5} \]

    \[ 1 \frac{3}{5} = \frac{1 \times 5 + 3}{5} = \frac{5 + 3}{5} = \frac{8}{5} \]

    \[ 2 \frac{1}{5} = \frac{2 \times 5 + 1}{5} = \frac{10 + 1}{5} = \frac{11}{5} \]

    The integer \(10\) can be expressed as \(\frac{50}{5}\).

  2. Substitute these values into the expression:

    \[ \frac{91}{5} + \frac{8}{5} - \frac{11}{5} - \frac{50}{5} \]

  3. Combine the fractions:

    \[ = \frac{91 + 8 - 11 - 50}{5} = \frac{91 + 8 - 11 - 50}{5} = \frac{38}{5} \]

  4. Convert \(\frac{38}{5}\) back to a mixed number:

    \[ 38 \div 5 = 7 \quad \text{(remainder } 3\text{)} \]

    Thus,

    \[ \frac{38}{5} = 7 \frac{3}{5} \]

Now, let's compare this result to the options provided:

  • \(12 \frac{2}{5}\)
  • \(17 \frac{2}{5}\)
  • \(-10 \frac{1}{5}\)
  • \(7 \frac{3}{5}\)

The final result is:

\[ \boxed{7 \frac{3}{5}} \]