please translate to english

No, the first translation has problem, 5分 should be 5 point, not 5 minutes.

This questionnaire contains two sub-scales: intrinsic and extrinsic motivations. There are totally 20 questions, which yields the "overall satisfaction" after calcuation. These scale employ a 5-point Likert scale, ranking from 1 as most unsatisfied to 5 as most satisfied.

In English questionnaire design, 量表 is scale, 子量表 is sub-scale. The 5-point scale you talked about also has a specific name: Likert scale (see link).

The questionnaire contains inherent meet Intrinsic motivation. external meet extrinsic two subscales, a total of 20 topics. If the 20 topics to meet the overall terms. And take five other assessment scales, and that by every one of the most dissatisfied, very satisfied with the five minutes to row.

Actually, the previous people translated is quite good. However, I would suggest as following:
This questionnaire contains Intrinsic and Extrinsic Motivation table. There is totally 20 questions. If all the 20 questions are included, it will classify as Satisfied. The survey uses 5 levels. Each question carriies from 1 mark to 5 marks.

2007-03-26 23:03:14 補充：
The last sentence should be modifed as following:Each question could be from 1 mark (very dissatisfy) to 5 mark (very satisfy).