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MATHEMATICS FOR AIR CREW TRAINEES       8

speed is 14 percent greater than the calibrated air speed. If the calibrated air speed is 172 mph, what is the true air speed?
First solution:  14 percent=.14
                .14X172 mph=24 mph
Therefore        172 mph+24mph=196 mph                 Answer. 
Second solution: 114 percent=1.14
                 1.14X172 mph=196 mph                  Answer. 

(c) Example: At a certain altitude and temperature, the true air speed is 14 percent greater than the calibrated air speed. If the true air speed is 210 mph, what is the calibrated speed?

Solution: Caution must be used in this type of problem. Percent increases as usually understood mean so many percent of the smaller number. Consequently, since 14 percent=.14, calibrated air speed+(.14)X(Calibrated air speed=210 mph
Therefore    (1.14) (calibrated air speed)=210 mph
or           calibrated air speed = (210 mph)/1,14
                                  = 184 mph             Answer.

This kind of problem can be checked very easily. Since 14 percent of calibrated air speed=.14X184=26 mph, 14 percent of calibrated air+calibrated air speed=26 mph+184 mph=210 mph
                                                        Check.
(4) To change a common fraction to a percent, first change the fraction to a decimal and then change the decimal to a percent. 

(a) Example: Express 3/4 as a percent.

    Solution: 3/4=.75=75%

(b) Example: Express 1/3 as a percent. 

    Solution: 1/3=.333 . . .=33.33 . . .% or 33 1/3%    Answer. 

(5) All types of percentage problems may easily be solved by the "equation: method.
(a) Example: What is 65% of 220?
    Solution: x is 65% od 220
              x=(.65)(220)'
              x=143                                      Answer. 

NOTE.-"Is: always stands for "equals." "Of" always stands for "times." In the equation the percent must be used in the decimal form. 
(b) Example: 250 is what percent of 900?
    Solution: 250=x . 900
             x=250/900=.28=28%                           Answer. 

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