Numbers Basics 1/1



1.  If x is even, y is odd, then which of the following are false?
a.  $x(x + y)$ is even
b.  ${x^n} \times {y^n}$ is even
c.  $3x + 5y$ is odd
d.  $\left( {{x^2} + x - 1} \right)\left( {{y^2} + y - 1} \right)$ is even


2.  Let \(x,y\) are even numbers and \(z\) is an odd number. Then which of the following is false?
a.  \({\left( {x - z} \right)^2}\) is odd number
b.  \(\left( {x - y} \right)z\) is even number
c.  \(\left( {z - x} \right){y^2}\) is even number
d.  \({\left( {x - y} \right)^2} + z\) is even number


3.  Which of the following is a prime number?
a.  221
b.  323
c.  629
d.  727


4.  Let \(x\) be prime and \(y\) be composite. Then
a.  \(xy\) is always even
b.  \(y - x\) is never even
c.  \(\dfrac{{x + y}}{x}\) is never even
d.  None of the above


5.  Prime factorization of 12600 is
a.  \({2^3} \times {3^2} \times {5^2} \times 7\)
b.  \({2^2} \times {3^2} \times {5^2} \times 7\)
c.  \({2^2} \times {3^2} \times {5^3} \times 7\)
d.  \({2^1} \times {3^1} \times {5^2} \times 7\)


6.  What least number must be subtracted from 12702 to get number exactly 99 ?
a.  49
b.  30
c.  29
d.  31


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