২২৬০১
What is the area of a circle with a radius of 7 meters?
উত্তর
154 sq metres
সমাধান
Area = π R2 = 22/7 × 72 = 154 m2
২২৬০২
How much would I have to pay for a book which cost Rs. 72 to produce, if the printing company sold it to a book seller at 20% profit and the bookseller sold it to me at a profit of 25%?
উত্তর
Rs. 108
সমাধান
Book seller's buying price = 72 + 20% of 72 = 72 + 14.4 = 86.4 Rs.
Book seller's selling price = 86.4 + 25% of 86.4 = 108 Rs.
২২৬০৩
A sum of 24 is divided into two parts so that seven times the first part added to five times the second part makes 146. The value of first part is?
উত্তর
13
সমাধান
Let the value of first and second part be F and (24 - F) respectively.
Now, 7F + 5(24 - F) = 146
or, 7F + 120 - 5F = 146
or, 2F = 146 - 120
or, F = 26/2 = 13
২২৬০৪
A sum of Rs. 1500.00 was put in two companies, one paid 6% simple interest and the other 5%. The whole annual interest from the two companies was Rs.85.00. What is the sum invested in the first company?
উত্তর
Rs. 1000
সমাধান
Let the investments be F and (1500 - F) Rs. in the companies respectively.
Interest, I = P n r
Now, F × 1 × 6/100 + (1500 - F) × 1 × 5/100 = 85
or, 6F + 7500 - 5F = 8500 [multiplying both sides by 100]
or, F = 8500 - 7500
or, F = 1000 Rs.
২২৬০৫
How many signals can be given by 5 flags of different colours using 3 flags at a time.
উত্তর
60
সমাধান
Possible ways = 5P3 = 5 × 4 × 3 = 60 [Ways of choosing 3 flags from 5 flags is 5C3. But different signals can be given bay rearranging those 3 flags in 3! ways. So, total possible ways of giving signal = 5C3× 3! = 5P3]
২২৬০৬
On selling 17 balls for Tk 720 , there iss a loss equal to the cost price of 5 balls. The cost price of a ball is --
উত্তর
Tk 60
সমাধান
(Cost price of 17 balls) - ( selling price of 17 balls) = ( cost price of 5 balls)
Cost price of 12 balls = selling price of 17 balls = Tk.720
Cost price of 1 ball = Tk 720/12 = Tk.60
২২৬০৭
If the average of 5 consecutive integers is 12, find the smallest integer.
উত্তর
10
সমাধান
The third number is the average number of 5 consecutive integers.
So, the smallest integer is = 12 - 2 = 10
২২৬০৮
Which of the following is a solution to the equation x+x2=1 ---
উত্তর
None of these
সমাধান
x+2x=1 or, x=⅓ as there is no right answer, so the answer will be none of these.
২২৬০৯
An industrial loom weaves 0.128 metres of cloth every second. Approximately , how many seconds will it take for the loom to weave 25 metres of cloth?
উত্তর
195
সমাধান
25 ÷ 128 = 195.3125 seconds
২২৬১০
If the length of a rectangle is increased by 20% and the width is decreased by 20%, then the area is:
উত্তর
decreased by 4%
সমাধান
We can let L = the original length
and W = the original width
Thus, the original area of the rectangular is LW and the new area is 1.2L× 0.8W = 0.96LW
So, the area is decreased by 4%