Five times of a positive integer is 3 less than twice the square of that number. The number is -
A. 3
B. 13
C. 23
D. 33
Answer: Option A
Solution(By Examveda Team)
$$\eqalign{ & {\text{Let }}x{\text{ is the number}} \cr & {\text{According to question,}} \cr & 5x = 2{x^2} - 3 \cr & 2{x^2} - 5x - 3 = 0 \cr & 2{x^2} - 6x + x - 3 = 0 \cr & 2x\left( {x - 3} \right) + 1\left( {x - 3} \right) = 0 \cr & \left( {2x + 1} \right)\left( {x - 3} \right) = 0 \cr & x = 3 \cr} $$Related Questions on Number System
Three numbers are in ratio 1 : 2 : 3 and HCF is 12. The numbers are:
A. 12, 24, 36
B. 11, 22, 33
C. 12, 24, 32
D. 5, 10, 15
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