Mathematics MCQs / Q&A

(i). a2 – 7a + 12 = 0, (ii). b2 – 3b + 2 = 0 to solve both the equations to find the values of a and b?

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(i). a2 – 7a + 12 = 0,
(ii). b2 – 3b + 2 = 0 to solve both the equations to find the values of a and b?

A. if a < b
B. if a ≤ b
C. if the relationship between a and b cannot be established.
D. if a > b (Correct)

Explanation:

I.(a – 3)(a – 4) = 0
=> a = 3, 4
II. (b – 2)(b – 1) = 0
=> b = 1, 2
=> a > b

 

 

 

 

I. x2 – x – 42 = 0, II. y2 – 17y + 72 = 0 to solve both the equations to find the values of x and y?

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I. x2 – x – 42 = 0,
II. y2 – 17y + 72 = 0 to solve both the equations to find the values of x and y?

A. If x < y (Correct)
B. If x > y
C. If x ≤ y
D. If x ≥ y
E. If x = y or the relationship between x and y cannot be established.

Explanation:

I. x2 – 7x + 6x – 42 = 0
=> (x – 7)(x + 6) = 0 => x = 7, -6
II. y2 – 8y – 9y + 72 = 0
=> (y – 8)(y – 9) = 0 => y = 8, 9
=> x < y

 

Masood purchased a plot for Rs. 8,000. He sells the plot to Aftab at a profit of 20%. Aftab in turn sells that plot to Zahid at a loss of 20%. The plot costs Zahid ?

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Masood purchased a plot for Rs. 8,000. He sells the plot to Aftab at a profit of 20%. Aftab in turn sells that plot to Zahid at a loss of 20%. The plot costs Zahid ?

 

A. Rs. 12,000
B. Rs. 10,000
C. Rs. 8670
D. Rs. 7680(Correct)

 

8000 x 20 / 100 = 1600 (so Masood earns 1600 profit (20%)

Aftab Purchase plot at 8000 + (20% which is 1600 ) = 9600

20% of 9600 = 1920 (Loss of Aftab)

So The plot costs Zahid: 9600 -1920 = 7680