Pubali Bank Ltd. - Probationary Junior Officer

Question: The ratio of two numbers is 3 : 4 and their H.C.F is 4. Their L.C.M is:
 
Solution:
ধরি,
সংখ্যা দুইটি যথাক্রমে 3x, 4x
 3x, 4x এর লসাগু = 12x
3x, 4x এর গসাগু = x

প্রশ্নমতে,
x = 4

∴  3x, 4x এর লসাগু = 12x
= 12 × 4
= 48

Question: If 2 tables and 3 chairs cost Tk. 3500 and 3 tables and 2 chairs cost Tk. 4000, then how much does a table cost?

Solution:
Let
The cost of a table and that of a chair be Tk. x and Tk. y respectively.

Then,
2x + 3y = 3500................(i)
and
3x + 2y = 4000................(ii)

(ii)× 3 - (i) × 2 ⇒
9x + 6y - 4x - 6y = 12000 - 7000
5x = 5000
x = 1000

The cost of a table Tk. 1000

Question: The sum of the two numbers is 22. Five times one number is equal to 6 times the other. The bigger of the two numbers is:

Solution:
Let,
The required number are x and y

Now
x + y = 22...........(1)

Five times one number is  equal to 6 times the other,
5x = 6y
x = 6y/5..............(2)

(1)⇒
6y/5 + y = 22
(6y + 5y)/5 = 22
11y/5 = 22
y/5 = 2
y = 10

(2)⇒
x = (6 × 10)/5
x = 12

Question: 36 men can complete a piece of work in 18 days. In how many days will 27 men complete the same work?

Solution:
৩৬ জন লোকে একটি কাজ করতে পারে ১৮ দিনে
১ জন লোকে একটি কাজ করতে পারে ১৮ × ৩৬ দিনে
২৭ জন লোকে একটি কাজ করতে পারে (১৮ × ৩৬)/২৭ দিনে
= ২৪ দিনে