The average score obtained by 64 boys and a certain number of girls
The average score obtained by 64 boys and a certain number of girls in a test is 59. 15, while the average score obtained by the boys is 55.25. If the average score of the girls is 68.75, then how many girls appeared for the test?
एक परीक्षा में 64 लड़कों और एक निश्चित संख्या में लड़कियों द्वारा प्राप्त औसत का 59.15 है, जबकि लड़कों द्वारा प्राप्त औसत अंक 55.25 है।यदि लड़कियों का औसत अंक 68.75 है,तो कितनी लड़कियों ने परीक्षा दी?
Detailed Solution & Logic
Correct Answer:
26
Let number of girls = $ x $
$ 64 \times 55.25 = 3536 $
$ x \times 68.75 = 68.75x $
$ 59.15(64 + x) = 3785.6 + 59.15x $
Now the equation:
$ 3536 + 68.75x = 3785.6 + 59.15x $
$ (68.75 - 59.15)x = 3785.6 - 3536 $
$ 9.6x = 249.6 $
$ x = \frac{249.6}{9.6} = 26 $
Answer = 26
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