1. Association option
If two of the topic options meet some equivalence relation in the topic, then it is very likely that one of the two related options is an interference item and the other is a correct answer.
For example:
(20 17- Beijing) A cocktail with an alcohol concentration of 20% was made up of liquor A, liquor A B and liquor A C with an alcohol concentration of 10% according to the ratio of 1:3: 1. It is known that the alcohol concentration of wine B is half that of wine A, and the alcohol concentration of wine A is 36%.
It is known that the alcohol concentration of liquor B is half that of liquor A, and it is found that option D is half that of liquor A. Let's assume that the alcohol concentration of liquor A is 36%. But sometimes, the equivalence between the two options is not obvious, and candidates need to explore for themselves.
2. Common sense of life
Everything is connected, and the problems all come from life. In fact, many times, common sense of life can often help us get rid of problems.
For example:
(20 14- nationwide) Two students need to check their luggage. The freight standard is/kloc-6 yuan/kg below 0/0 kg, and the charging standard per kg for the part exceeding 10 kg is slightly lower. It is known that the freight charges of Party A and Party B are 109.5 Yuan and 78 yuan respectively, and Party A's luggage is 50% heavier than Party B's ... Then, the charging standard per kilogram for the part exceeding 10 kg is lower than that for the part within 10 kg/5 yuan.
It can be seen from the "slightly lower" charging standard that the slightly lower charging standard should be given priority. If 2.5 yuan is reduced, it has been reduced by about 50%, which is slightly lower.
3. Extreme assumptions
When the topic involves a huge amount of calculation, we might as well assume the most extreme (special) situation, and then compare the actual situation with the assumed extreme situation to get the answer.
For example:
(20 14- joint entrance exam) The factory needs to process a batch of parts, with Party A working alone for 96 hours, Party B for 90 hours and Party C for 80 hours ... Now, according to the order of the first day of cooperation, the second day of cooperation and the third day of cooperation, Party A and Party C work in shifts, working 8 hours a day. When all the parts were finished, A worked for 32 hours.