২০৯৬১
There is a 2 meter wide rode surrounding a pond which is 60 meters long and 40 meters wide. The area (in sq meters) covered by the road is:
উত্তর
416
সমাধান
(64 ×44) - (60 ×40) = 416
২০৯৬২
If x+y =9 and x-y =5, the value of 4xy is:
উত্তর
56
সমাধান
x + y = 9
x - y = 5
4xy = ( x + y) 2 - ( x - y) 2
= 81 - 25
= 56
২০৯৬৩
Tk 51 is distributed between Sumi and Meen in such a way that Sumi receives Tk 3 less than twice the amount received by Meem. The amount (in Taka) received by Sumi is:
উত্তর
33
সমাধান
Let, Meem = x
Sumi = 2x - 3
So, x + 2x - 3 = 51
3x = 54
x = 18
Sumi = 18 × 2 - 3 = 33 ( Tk.)
২০৯৬৪
The compound interest (in Taka) on Tk 200 at 10% in 3 years is approximately:
উত্তর
66
সমাধান
Compound interest = C - P = P(1 + r)n - P
= 200 x (1 + 0.1)3 - 200
= 66.2 TK (Ans)
২০৯৬৫
The ratio of ages of a father and his son his son was 5: 1. What is the age of the son after five years, if the ratio of their ages is 3: 1 by this time?
উত্তর
10
সমাধান
Father = 5x
Son = x
So, ( 5x + 5) : ( x + 5) = 3 : 1
5x + 5)/ x + 5 = 3/1
5x + 5 = 3x + 15
2x = 10
x = 5
After 5 years son age = 5 + 5 = 10
২০৯৬৬
One half of a pole is deep into the soil under water, one-third of it is above the soil under water and 2 meters of it is above the water level. The total length of the pole in meters is:
উত্তর
12
সমাধান
1 - ( 1/2 + 1/3) = 1 - ( 3 + 2/6)
6 - 5 / 6 = 1/6
So, 1/6 portion = 2 meter
1 portion = 6 × 2 = 12 meter
২০৯৬৭
At a selling price of Tk 273 a book yields 30% profit. What selling price (in Taka) will yield the profit of 10%?
উত্তর
231
সমাধান
At 30% profit ,
If selling price is Tk.130 then cost is Tk.100
If selling price is Tk 273 then cost is Tk = (100×273)/130 = Tk.210
Selling price = 210 + 210 ×10% = 210 + 21 = 231
২০৯৬৮
What is the volume of a cube that has a total surface area of 54?
উত্তর
27
সমাধান
Total surface area, 6a2 = 54
Where a = one side.
So, Volume a3 = 33
a = 3
২০৯৬৯
The product of two numbers is 900 and their sum exceeds their difference by 30. the greater of these two numbers is:
উত্তর
60
সমাধান
One number = x
Another number = 900/x
x + 900/x = ( x - 900/x) + 30
2. 900/x = 30
x = (2 ×900)/ 30
x = 60
২০৯৭০
Alam spent 20% of his income on taxes and 20% of the reminder on rent. What per cent of his income he has spent on rent?
উত্তর
16
সমাধান
( 100 - 20) × 20%
= 80 × 20/100
= 16