A box contains 200 pens of which 25% are… | Answer

Subject

Quantitative Aptitude

Topic

Percentage

A box contains 200 pens of which 25% are red and the rest are black. You sold a certain number of pens of which 60% were black. You then found that among the remaining pens, only 20% are red. How many pens did you sell?
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ক)

খ)

গ)

ঘ)

ঙ)

None

Explanation

ধরি, বিক্রি করা কলমের সংখ্যা = x প্রাথমিকভাবে বাক্সে ছিল: মোট কলম = 200 টি লাল কলম = 200 * (25/100) = 50 টি কালো কলম = 200 - 50 = 150 টি বিক্রি করা কলমের মধ্যে: কালো কলম = x * (60/100) = (3/5)x টি বাক্সে বাকি থাকা কলমের মধ্যে: মোট বাকি থাকা কলম = 200 - x টি লাল কলম = (200 - x) * (20/100) = (200 - x) * (1/5) = (40 - x/5) টি প্রাথমিকভাবে বাক্সে থাকা লাল কলম - বিক্রি করা লাল কলম = বাক্সে বাকি থাকা লাল কলম ⇒ 50 - (x - (3/5)x) = 40 - x/5 ⇒ 50 - (2/5)x = 40 - x/5 ⇒ (1/5)x = 10 ⇒ x = 50 সুতরাং, বিক্রি করা কলমের সংখ্যা হলো 50 টি।

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A box contains 200 pens of which 25% are red and the rest are black. You sold a certain number of pens of which 60% were black. You then found that among the remaining pens, only 20% are red. How many pens did you sell?Reading

A box contains 200 pens of which 25% are red and the rest are black. You sold a certain number of pens of which 60% were black. You then found that among the remaining pens, only 20% are red. How many pens did you sell?

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A box contains 200 pens of which 25% are red and the rest are black. You sold a certain number of pens of which 60% were black. You then found that among the remaining pens, only 20% are red. How many pens did you sell?
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