Jamuna Bank Ltd. 2014 (PO)

At a party, everyone shook hands with everybody else. If there were 66 handshakes, how many people were at the party?

ক) 9 খ) 10 গ) 12 ঘ) 13

ব্যাখ্যা (Explanation)

Let the number of persons= n

Number of handshakes by first person= n- 1

(As he cannot handshake with himself)

Number of handshakes by second person = n- 2

(As he has already handshaked with first person)

Number of handshakes by third person= n- 3

.

Number of handshakes by second last i.e. ( n- 1)th person= n- (n- 1)= 1

Number of handshakes by last i.e. nth person= n- n= 0

So,

Total number of handshakes=(n- 1)+ (n- 2)+ (n- 3)+ 1+ 0

= 0+ 1+ 2+ 3+ ...........(n- 1)

= Sum of first (n- 1) terms

= (n- 1)(n- 1+ 1)/2

= n(n- 1)/ 2

So, Total number of handshakes= n(n- 1)/2

According to question,

n(n- 1)/ 2= 66

=> n^2 - n= 132

=> n^2- n- 132= 0

=> n^2- 12n+ 11n- 132= 0

=> n(n- 12) + 11(n- 12)= 0

=> (n- 12)(n+ 11) = 0

n= 12 or n= - 11(which is not possible as no. Of persons cannot be negat

I read an advertisement that said P: posh, air-conditioned Q: gentlemen of taste R: are available for S: fully furnished rooms

ক) SPQR খ) PSRQ গ) QPSR ঘ) RQPS

The solid brick shown is made of small square shaped bricks of side When the large brick is disassembled into its component small bricks. the total surface area of all the small bricks is how much greater than the surface area of the large brick?

ক) 32 খ) 40 গ) 60 ঘ) 72

ব্যাখ্যা (Explanation)

here, small cube shped brick=12 we know, surface of cube=6 x (arm)2 total surface of 12 bric=12x6x(1)2=72 now, length= 3 cm width= 2 cm height=2 cm rectangle er surface=2(ab+bc+ca)=2[(3x2)+(2x2)+(2x3)=32 small-big=72-32=40

A jar contains 4 red toothpicks, 10 blue toothpicks and 6 yellow toothpicks. If three toothpicks are removed from the bag at random and no toothpick is returned to the bag after removal, what is the probability that all three toothpicks will be blue?

ক) 1/2 খ) 1/8 গ) 3/20 ঘ) 2/19

ব্যাখ্যা (Explanation)

probablity=10/20 x 9/19 x 8/18=2/19

A survey of City A found an average (arithmatic mean) of 2 people per household and an average of 2 DVD players per household. If 48000 people live in City A, how many DVD players are there in City A?

ক) 15000 খ) 16000 গ) 18000 ঘ) 40000

ব্যাখ্যা (Explanation)

3.2 people live in 1 house hold 1 people live in 1/3.2 house hold 48000 people live in 48000/3.2 house hold=15000 household in 1 household the is 1.2 dvd in 15000 household 1.2x15000=18000 dvd

Rafia ran from her house to school at an average speed of 6 miles per hour and returned along the same route at an average speed of 4 miles per hour. If it took her one hour in total to run to the school and come back, how many minutes did it take her to run from her house to school?

ক) 16 খ) 18 গ) 20 ঘ) 22

ব্যাখ্যা (Explanation)

suppose, distance=D we know, time=distance/speed at time of going=D/6 t time of coming=D/4 here, D/6+D/4=1 or,D=12/5 miles goes 1 mile in 1/6 hour goes 12/5 milein 1/6 x 12/5 hour=2/5 hour =24 minutes

Afia can do her term paper in 15 days which takes Babul 20 days to finish, What is the fraction of work left if both Afia & Babul work together for 4 days?

ক) 1/4 খ) 1/10 গ) 7/15 ঘ) 8/15

ব্যাখ্যা (Explanation)

Afia, in 15 days does 1 work in 4 days does 4/15 work Bbul, in 20 days do 1 work in 4 days do 4/20 work both of them do together=(4/15+4/20)=7/15 part left=(1-7/15)=8/15

3, 12, 30, 39 are the first five terms of a sequence. Each term after the first is obtained by adding 9 to the term immediately preceding it. Which term in the sequence is equal to 3+(33-1)9?(3, 12, 30, 39 একটি অনুক্রমের প্রথম পাঁচটি পদ। প্রথম পদের পরে প্রতিটি পদের সাথে 9 যোগ হয়ে ক্রমটি চলমান থাকে।। অনুক্রমের কোন পদটি 3+(33-1)9 এর সমান?)

ক) 8th খ) 9th গ) 32nd ঘ) 33rd

ব্যাখ্যা (Explanation)

2nd term=3+(2-1)9=12 3rd term=3+(3-1)9= 21 1 st number in the bracket indicates the term 3+(33-1)9 , here 1 st number in the bracket indicates the 33rd term

What is the minimum number of chocolates that must be added to an existing stock of 966 chocolates, so that the total stock can be equally distributed among 6, 7, 8 or 9 persons?

ক) 36 খ) 42 গ) 56 ঘ) 72

ব্যাখ্যা (Explanation)

prime factors of following numbers are, 6=2x3 7=1x7 8=2x2x2x2 9=3x3 so,L.C.M=2x3x3x7x4=504

In a college, 45% of the students are boys. If 40% of the boys and 20% of the girls went on a picnic, what percentage of the total students went to the picnic?

ক) 18% খ) 24% গ) 29 ঘ) 30%

ব্যাখ্যা (Explanation)

boys =45% so,girls=100-45=55%

boys went to picnic=40% of 45 %=18% girls went to picnic=55% of 20%=11% total student=(18+11)=29%

A survey showed that 63% of Bengali people like chicken where as 76% like fish. If x% on them like both fish and chicken, then what is the range of x?

ক) 0 ≤ x ≤ 23% খ) 0 ≤ x ≤ 39% গ) 4 ≤ x ≤ 35% ঘ) 6 ≤ x ≤ 33%

ব্যাখ্যা (Explanation)

suppose, people like both x% total people 100% here, x%=(63+76)%-100%=39%

Present age of Farzana is thrice the present age of Samira who is How many years ago were the age of Farzana five times that of Samira?

ক) 3 খ) 10 গ) 7.5 ঘ) 6

ব্যাখ্যা (Explanation)

samiras age=20 farzanas age=60 suppose, x years ago farzana was five times of samira according to question, (20-x)5=60-x or,4x=40 or,x=10

Mr. Ahsan is insured completely for Tk. 50000 of damages to his car. For any damage above Tk. 50000 the insurance company will pay Tk. 50000 plus 20% of the rest of the damage amount. For a recent accident, Mr. Ahsan was paid 56000 by the insurance company. What was the total amount of the damage estimated?

ক) Tk. 30,000 খ) Tk. 2,80,000 গ) Tk. 1,04,000 ঘ) Tk. 80,000

ব্যাখ্যা (Explanation)

damage insured=50000 tk damage paid by company=56000 tk damage extra paid=6000 tk

In a library, of the books standing in a row on a shelf, an atlas is the 30^th book from the left and the 33^rd book from the right. If 2 books to the left of the atlas and 4 books to the right of the atlas are removed from the shelf, how many books will be left on the shelf?

ক) 56 খ) 57 গ) 58 ঘ) 61

ব্যাখ্যা (Explanation)

left books=(29-2)+(32-4)+1=56

A school has raised 75% of the amount it needs for a new building by receiving an average donation of Tk 60 from the people already solicited. The people already solicited represent 60% of the people the college will ask for donations. If the college is to raise exactly the amount needed for the new building, how much must the remaining people donate per person?

ক) Tk 25 খ) Tk30 গ) Tk 40 ঘ) Tk 50

ব্যাখ্যা (Explanation)

suppose, total people 100 60% means, 60 people gve 60 tk, then total= 60x60=3600 tk people remain= 40 money remin=3600x100/75=4800-3600=1200 tk so remaining per people donate =1200/40=30 tk

Buffet dinner at a restaurant costs Tk. 3550(excluding sales tax). If the sales tax was more than 10 percent but less than 15 percent of the pre-tax cost of the dinner, then the total amount paid must have been between---