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%.
Solution:
The cost price = (3600 × 100)/125 = 2880
New selling price = Tk. 2700
∴ Loss = 2880 - 2700 = 180
∴ Loss percentage = (100 × 180)/2880 = 6.25%.
Solution:
Let the original price of the TV be 1000 Taka.
Wholesaler’s discount = 25%
Retailer’s purchase price:
1000 − 25% of 1000 = 1000−250 = 750 Taka
Retailer’s markup = 50% on Taka 750
New marked price:
750 + 50% of 750 = 750 + 375 = 1125 Taka
Customer’s discount = 20% on Taka 1125
Selling price:
1125 − 20% of 1125 = 1125 − 225 = 900 Taka
So, Profit = {(900 - 750)/750} × 100%
= 20%
Solution:
Cost of first variety = 250 Taka/kg
Cost of second variety = 350 Taka/kg
Ratio = 3:2
Cost price of mixture = {(3×250) +(2×350)}/(3+2)
= 1450/5
= 290 Taka/kg
Profit = Selling price - Cost price
= 360 - 290
= 70 Taka/kg
Profit percentage = (70/290) × 100%
= 24.13%
= 25%
Solution:
Let,
The price of an article is 100 Tk.
If the price increased by 25%,
So, the new price will be after increase = 100 + {100 × (25/100)} Tk.
= 100 + 25 Tk.
= 125 Tk.
Then the new price decreased by 20%,
So, the new price will be after decrease = 125 - {125 × (20/100)} Tk.
= 125 - 25 Tk.
= 100 Tk.
∴ The net effect on the price of the article is = (100 - 100)
= 0 Taka
So, after both the increase and the decrease, the price remains the same.
Solution:
The cost price of each gem is 20 per Tk. = Tk. 1/20
The price of each gem is 30 per Tk. = Tk. 1/30
∴ Average cost of gem = {(1/20) + (1/30)}/2
= (3 + 2)/(2 × 60)
= 5/120
= 1/24
The selling price of mixed gem = Tk. 1/25
∴ Loss = (1/24) - (1/25) = 1/600
Cost price 1/24 then loss Tk. 1/600
Cost price 1 then loss Tk. (1/600)/(1/24)
∴ Cost price 1 then loss Tk. {(1/600)/(1/24)} × 100 = 4%
∴ There is a loss of 4%