বিগত সালের প্রশ্ন ও প্রশ্ন ব্যাংক
বিসিএস, ব্যাংক, প্রাথমিক শিক্ষক ও সকল সরকারি চাকরির বিগত সালের প্রশ্ন ও অধ্যায়ভিত্তিক নির্ভুল সমাধান
Solution:
We can let the original length = 4, and the original width = 10.
So the original area is 40.
When the length increases by 25%
we have 4 × 1.25 = 5
Thus, for the area to remain 40, the width must be 8.
Since {(8 - 10)/10} × 100 = - 20, we see that 8 is 20 percent less than 10. In other words, the width has to decrease by 20%.
বাংলাদেশের স্বাধীনতা যুদ্ধে বীরত্বের জন্য 'বীর প্রতীক' খেতাবপ্রাপ্ত একমাত্র বিদেশি নাগরিক কোন দেশের?
Solution:
Good at Mathematics n(M) = 65
Good at Statistics n(S) = 45
good in both Mathematics and Statistics n(M ∩ S)
We know that
n(M ∪ S) = n(M) + n(S) - n(M ∩ S)
⇒ n(M ∩ S) = n(M) + n(S) - n(M ∪ S)
= 65 + 45 - 100 = 110 - 100 = 10
Solution:
Let Cost Price was x
ATQ,
x + 14% of x = 2850
⇒ x + 14x/100 = 2850
⇒ x + 0.14x = 2850
⇒ 1.14x = 2850
⇒ x = 2850/1.14
∴ x = 2500
So, Cost Price = 2500
Now, Selling Price When profit remains at 8%,
= 2500 + 8% of 2500
= 2500 + 200 = Tk. 2700
Solution:
Original price of the toothbrush: Tk. 50
Price increase: 20%
New price of toothbrush = 50 + {(20/100) × 50} = 50 + 10 = Tk. 60
Original price of the comb: Tk. 50
Price decrease: 10%
New price of comb = 50 - {(10/100) × 50} = 50 - 5 = Tk. 45
Difference = 60 - 45 = Tk. 15
The difference in Taka between the current price of the toothbrush and the comb is Tk. 15.
Solution:
Original cost: Tk. 150 for a package of 3 pens.
Cost per pen originally: Original cost per pen = 150/3 = Tk. 50 per pen
New cost: Tk. 300 for a package of 5 pens.
Cost per pen now: New cost per pen=300/5 = Tk. 60 per pen
Increase in cost = 60 - 50 = Tk. 10 per pen
Percent increase = (10/50) × 100 = 20%