721:221=
To solve the problem of dividing the mixed numbers 721 by 221, follow these steps:
- Step 1: Convert the mixed numbers to improper fractions.
- Step 2: Divide the fractions by multiplying by the reciprocal.
- Step 3: Simplify the resulting fraction to find the answer.
Now, let’s break it down step-by-step:
Step 1: Convert 721 to an improper fraction. To do this, multiply the whole number 7 by the denominator 2 and add the numerator 1:
7×2+1=14+1=15.
This makes the improper fraction 215.
Convert 221 in a similar manner:
2×2+1=4+1=5, giving 25.
Step 2: Divide 215 by 25 by multiplying 215 by the reciprocal of 25, which is 52:
215×52=2×515×2=1030.
Step 3: Simplify 1030: divide the numerator and the denominator by their greatest common divisor, 10,
1030=10÷1030÷10=13=3.
Therefore, the solution to 721÷221 is 3, which corresponds to choice 3.