[機經] 請教8月數學 No.307
307 PS: In a research, 15% of the plants ( developed fungus and died ), 40%
of the plants ( who developed fungus but not died ), what is the percentage
of the plants developed fungus?
A. 25%
B. 27%
C. 35%
D. 40%
E. 55%
CD上給的答案是55%, 可是我自己算出的結果是25%
式子如下:
假設 X%=percentage of the plants developed fungus
則感染fungus且有死掉的 = 15% = X%（1-40%）
求出 X%=25%
但是不確定這樣是否正確...
是否把題目想得太複雜?
還請會的人幫忙解釋!!
Thanks!
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