২১৯৮১
একজন বিক্রেতা একটি পন্য ৪৮০ টাকায় বিক্রি করে ২০% লাভ করল। পণ্যটির ক্রয়মূল্য কত টাকা?
উত্তর
400
সমাধান
২০% লাভে,
বিক্রয়মূল্য ১২০ টাকা হলে ক্রয়মূল্য ১০০ টাকা
বিক্রয়মূল্য ৪৮০ টাকা হলে ক্রয়মূল্য ১০০ x ৪৮০ / ১২০ = ৪০০ টাকা
২১৯৮২
If ab-2cd = p; 6cd-3ab=1; what is the value of p?
উত্তর
-1/3
সমাধান
Given That , 6cd - 3ab = 1 ⇒ 3(2cd - ab) = 1 ⇒ 2cd - ab = 13 another equation is, ab - 2cd = p ⇒ -1(2cd - ab)= p ⇒ -13 = p (putting the value of 2cd - ab) Ans: P = -13
২১৯৮৩
A club has 8 male and 8 female members, the club is choosing a committee of 6 members. The committee must have 3 male and 3 female members. In how many ways can the committee chosen?
উত্তর
3,136
সমাধান
Since there are 8 male and female membersand we need to choose 3 members each for the committee,we could choose them as follows: 8c3∗8c3 = 562 = 3136
২১৯৮৪
A arden is 60m long and 20m wide. Inside the garden there is a 5m wide path around it. The area of the path is in square meter.
উত্তর
700
সমাধান
Area including path = 60 x 20 = 1200 sq. m.
Length without path = 60 - (5x2) = 50 m
Width without path = 20 - (5x2) = 10 m
Area without path = 50 x 10 = 500 sq. m.
Area of the path = 1200 - 500 = 700 sq. m.
২১৯৮৫
How many students can sit in a room with n single chairs and b doubleseated benches?
উত্তর
2b + n
সমাধান
In 1 single chair seated 1 student So, in n single chair seated = 1 × n= n studentsAgain, In 1 bench, seated 2 studentsSo, in b bench seated = 2 × b = 2b students So Total number of Student can be seated in this classroom is = 2b + n Ans: 2b+n
২১৯৮৬
Point X is North of point Y , which is East of point Z. To which direction is point X with respect to point Z?
উত্তর
South-West
সমাধান
Q. Point X is North of point Y , which is East of point Z. To which direction is point X with respect to point Z ?প্রশ্নে, Z এর সাপেক্ষে X কোথায় অবস্থান করছে, সেটা জানতে চাওয়া হয়েছে।Follow the diagram:
২১৯৮৭
A circular flower bed has diameter 4m. The flower bed is increased so that the diameter is now 12m. How many times larger is the new flower bed?
উত্তর
9
সমাধান
In case of a circle, Area ∝ (diameter)2
So, A2/A1 = d22/d12
or, A2 = d22/d12 x A1
= 122/42 x A1
= 9 A1
২১৯৮৮
Molasses cost Tk. x for the first 1.5 kg at 'Prabartana'. All amount in addition to first 1.5 kg cost Tk. 50 per kg. How much does it cost to buy 5 kg molasses from 'prabartana'?
উত্তর
Tk. (x+175)
সমাধান
The cost of the first 1.5 kg of molasses is given as Tk. x.So, the cost of the remaining 5 - 1.5 = 3.5 kg of molasses will be 3.5 × 50 = Tk. 175.Therefore, the total cost of 5 kg of molasses will be:Cost of first 1.5 kg + Cost of remaining 3.5 kg= Tk. x + Tk. 175= Tk. (x + 175)Hence, the cost of 5 kg of molasses from 'Prabartana' is Tk. (x + 175).
২১৯৮৯
In a sugar-water solution, the ratio of water to sugar is 8: 3. If you add 2 Kgs of sugar, the ratio becomes 2: 1. What was the amount of sugar in the original solution?
উত্তর
6
সমাধান
W : S = 8 : 3
W/S = 8/3
3W = 8S
Again, W/(s + 2) = 2/1
1W = 2s + 4
3W = 6S + 12
8S = 6S + 12
S = 6
২১৯৯০
A man binds 112 books in a day , and his assistant work 1/4 as fast. How many days will it take them to bind 560 books, if each alone works on alternate days?
উত্তর
8
সমাধান
His assistant binds 1/4 x 112 = 28 books a day.
So, they bind 112 + 28 = 140 books in every 2 days working in alternate days
They will need 560/140 x 2 days = 8 days.