6. Given $a=\frac{11 \times 66+12 \times 67+13 \times 68+14 \times 69+15 \times 70}{11 \times 65+12 \times 66+13 \times 67+14 \times 68+15 \times 69} \times 100$, find: the integer part of $a$ is

what?
6. 101
6.【Solution】 $\mathrm{a}=\frac{11 \times 66+12 \times 67+13 \times 68+14 \times 69+15 \times 70}{11 \times 65+12 \times 66+13 \times 67+14 \times 68+15 \times 69} \times 100$
$$
\begin{array}{l}
=\frac{11 \times(65+1)+12 \times(66+1)+13 \times(67+1)+14 \times(68+1)+15 \times(69+1)}{11 \times 65+12 \times 66+13 \times 67+14 \times 68+15 \times 69} \times 100 \\
=\frac{(11 \times 65+12 \times 66+13 \times 67+14 \times 68+15 \times 69)+(11+12+13+14+15)}{11 \times 65+12 \times 66+13 \times 67+14 \times 68+15 \times 69} \times 100 \\
={ }^{\left(1+\frac{11+12+13+14+15}{11 \times 65+12 \times 66+13 \times 67+14 \times 68+15 \times 69}\right) \times 100} \\
={ }^{100+\frac{11+12+13+14+15}{11 \times 65+12 \times 66+13 \times 67+14 \times 68+15 \times 69} \times 100}
\end{array}
$$

Because, $\frac{11+12+13+14+15}{11 \times 65+12 \times 66+13 \times 67+14 \times 68+15 \times 69} \times 100\frac{100}{69}>1$

Therefore, the integer part of $\mathrm{a}$ is 101.