mathematical operations are important questions in the civil service examination administration occupation ability test, is also one of the most difficult questions, many candidates even this waiver, then in just over one month, how to quickly break through mathematical calculations? First, candidates are to be familiar with methods of solving problems on some general topics, such as the exclusion principle, cattle eat grass issues direct formula can be. In addition to mastery of thought and basic problem-solving skills. China figure education focus describes two species solving thought: equation and digital characteristics thought, and set special value thought
(1) equation and digital characteristics thought
digital characteristics method is solution many mathematics operations topic of effective method, but this method does not easy master, candidates is difficult to read finished questions on can thought by seeking of number has what characteristics, but candidates General on equation method is comparison familiar of, actually sometimes this two species method is communicates of, by set unknown we on can know by seeking of volume has what characteristics.
the "cases" of two shop purchase the same goods, shop a shop price b cheap 10%, a shop in the 20% of profit pricing, store in a 15% profit pricing, store pricing is higher than shop b $ 28, the shop price is ( )
A.330 $ & nbsp; B.360 $
C.370 $ D.400-element
"analyze" forbids an economic profit problem, usually through the column of solution of equation. Topic requirements of is methyl shop of into price, and methyl shop of into price than b shop cheap 10%, so under equation thought in the set unknown of "easy understanding" of principles, we usually set b shop of into price is x, is methyl shop of into price for 0.9x, is clearly methyl shop of into price for 9 of multiples, and options in is 9 of multiples of only b options. This question is difficult to glance a shop by the price is a multiple of 9, but through the unknown, it is very easy to see that a shop price is a multiple of 9.
the "cases" a company employs 830 people last year, men this year than last year's decline in the number of 6%, female employees than last year's increase in the number of 5% associates and 3 increase over the last year, asked male staff how many people this year?
A. 329 B.350
C. 371 D. 504
"analyze" forbids can also belong to the comparison of typical types of equations, men this year than last year's decline in the number of 6%, so we can set last year by male staff to x, the male staff for this year's 0.94x, set number of multiples of 0.94 male staff this year, can be found option only if a is a multiple of 0.94, so select a.
(2) set special value of thought
Dang topic in the no involved a specific volume of size, and this specific volume of size does not effect eventually results of when, we usually can with set special value of thought, will this volume set for a a conducive to calculation of numerical, to simplified calculation, this thought in we of engineering problem, and economic profit problem, and tour problem in the are has widely of application.
the "cases" a task requires about half an hour, b do 45 minutes, how many minutes you need both cooperation ( )
A.12 B.15
C.18 D.20
the "analysis" is beside the engineering problem. Beside the to out has methyl b separate completed task of time respectively is 30, and 45 minutes,
so on can set total for 90, is methyl each minutes completed 3, b each minutes completed 2, cooperation each minutes completed 5, so cooperation of time for 90 ÷ 5=18. selected C
"cases" a supermarket purchased into group commodity, in accordance with the can get 50% of profit pricing, results only sales has 70%, for do
fast will remaining of commodity sales out, supermarket decided discount sold, such by get of all profit is original can get profit of 82%, asked remaining of commodity several folded sold? ( )
A.6.5 Pack B. 70 percent
C.7.5 Pack D.8 folded
"cases" beside the belonging to economic profit problem, topic in no to out purchased into commodity of into price and buy of number, so we can set into price is 100, buy has 100 pieces commodity, is pricing for 150, profit is 50 Yuan, total can get of profit is 50x100=5000, discount sold Hou, eventually of profit becomes 5000x82%=4100, set discount Hou of commodity of profit for x, is 70x50+30x=4100, solutions was x=20, is discount Hou of price for 120, price is 150, so playing has 80 percent, selected D
"cases" A boat sailing from a to b to 4 hours, from b to a to 5 hours of navigation (assuming that the ship itself
speed remains the same), there is a raft from a drifting to this place the required hours for
A.12 B.40
C.32 D.30
"analyze" forbids is travelIssue. Topic in the no to out methyl b between of distance, only to out has navigation of time, is we can set distance is 20, so from methyl to b of speed for 5, is for times of speed, and upstream of speed, 20 ÷ 5=4, water speed for (5-4) ÷ 2=0.5, so rafting from methyl to drifting to b to by required hours for 20 ÷ 0.5 = 40 hours, selected B
digital characteristics thought and set special value is thought is we solving Shi common of thinking, course, to wanted to skilled master mathematics operations in the of solving skills, need candidates more long practiced, more see more wanted to, remember common of types of solution, skilled has speed only will fast, for behind of solving playing good foundation.
