Math, asked by didiindu59, 9 months ago

a boy gets 3 marks for each correct sum and loses 2 marks for each incorrect sum he does 24 sum and obtains 37 marks the number of correct sums were​

Answers

Answered by priyanshcd
2

Answer

Don't ask incomplete questions

Step-by-step explanation:

Answered by venupillai
6

Answer:

No. of correct sums = 17

Step-by-step explanation:

Let

No. of correct sums = x

No. of incorrect sums = y

He does 24 sums in all, hence:

x + y = 24 ..........(i)

Marks earned for each correct sum = 3

=> marks earned for "x" correct sums = 3x

Marks earned for each incorrect sum = -2

=> marks earned for "y" incorrect sums = -2y

(Note: negative marks earned means marks lost)

Total marks earned = 3x - 2y

We are given this to be 37

=> 3x - 2y = 37 ...........(ii)

Multiply (i) by 2

=> 2x + 2y = 48 ..........(iii)

Add (ii) and (iii)

=> 5x = 85

=> x = 17

No. of correct sums = 17

Using (i),

y = 24 - x

y = 24 - 17

y = 7

No. of incorrect sums = 7

Full answer:

No. of correct sums = 17

No. of incorrect sums = 7

Total sums done = 17 + 7 = 24 √

No. of marks earned from correct sums = 17*3 = 51

No. of marks earned for incorrect sums = 7*(-2) = -14

Total marks earned = 51 - 14 = 37 √

Hence, verified.

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