GRE Questions

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This is a quadratic equation. To find n we multiply the last terms in each bracket together (2 times -5) = -10

To find ‘a’ we multiply the first terms in each bracket together (3x times 2x) = 6x2, So a = 6.

Thus a - n = 16

To find k we multiply the first term in the first bracket by the second term in the second bracket and add the result to the product of the second term in the first bracket and the first term in the second. (-15x + 4x) = -11x. So k = -11

16 - 11 = 5

We know that,

● Each digit has a fixed position called its place.

● Each digit has a value depending on its place called the place value of the digit.

● The face value of a digit for any place in the given number is the value of the digit itself

● Place value of a digit = (face value of the digit) × (value of the place).

Hence, the place value of 6 in 64 = 6 x 10 = 60.

The given puzzle follows a logic that,

2 + 10 = 24 => 2 + 10 = 12 x 2 = 24

3 + 6 = 27 => 3 + 6 = 9 x 3 = 27

7 + 2 = 63 = 7 + 2 = 9 x 7 = 63

Similarly, 5 + 3 = 40 => 5 + 3 = 8 x 5 = 40.