GATE CSE 2019 | Question: GA-4

Question

Ten friends planned to share equally the cost of buying a gift for their teacher. When two of them decided not to contribute, each of the other friends had to pay Rs. $150$ more. The cost of the gift was Rs. ____

• A. $666$
• B. $3000$
• C. $6000$
• D. $12000$

Comments

6000 is answer

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6000

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150*8=1200

1200/2=600 each person

600*10=6000rs 

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600

Answer 1

Let x be the amount 1 person is contributing and y be the total amount
Now,

10(x) = y _________(1)
2(0) + 8(x+150) = y ___________(2)

8(x) + 1200 = 10(x)
=> 2(x) =1200

x = 600

therefore total amount, y = 10(x) = 6000

Answer 2

X = total gift
m= individual gift

X/10=m
X/8=m+150
X=8m+1200
X/10+150=x/8
8x+12000=10x
X=6000

Answer 3

suppose that  total cost of price is x   ( lets suppose amount is 80)

total number os students are 10 then each have to pay of  x/10 ( each have to pay 8)

now two students does not want to contribute so remaining students are 8 (new amount 10 so rs 2 rupees extra)

x/8=x/10+150 ( 80/8=80/10+2 )

5x-4x=150*40

x=600.

Answer 4

One simple way to do is:-  since each of other eight friends need to pay Rs.150 more, so 150*8=Rs.1200.

Rs. 1200 is actual contribution of 2 people (who have not actually paid).

So, contribution one 1 person=Rs.1200/2=Rs.600

Contribution of 10 persons= Rs.600*10=Rs.6000