First, convert the mixed fractions into improper fractions. This will make it easier for us to estimate:
6 and 4/11= 70/11
2 and 1/12= 25/12
Now, we know that 70 x 20 is 1400 and 10 x 12 is 120, so just add 350 to the numerator and 12 to the denominator to be more accurate:
1400 + 350 = 1750
120 + 12 = 132
Then put these two numbers into a fraction and simplify!
1750/132 = 875/66
= ~ 13
Hope this helps!
