Draw rough sketches of concave and convex quadrilaterals. Explain the properties which differentiate them.

Mark the correct alternative in the following.

The largest $5-$digit number using any one digit twice from digits $6, 8, 3, 1$is:

Mark the correct alternative in the following.

The sum of successor and predecessor of any $4-$digit number is always:

Mark the correct alternative in the following.

If LCM of two numbers is $30$, then which of the following cannot be their HCF?

A point where three or more lines meet is called:

The length of the longest chord of a circle of radius $5 \mathrm{cm}$ is

State True or False:

In Roman numeration, a symbol can be repeated to a maximum of $5$ times.

State True or False:

If $a,b,c$ are any three whole numbers, then $\left(a\times b\right)\times c=a\times \left(b\times c\right)$.

State True or False:

Prime factorization of $12$ is equal to $1\times 2\times 2\times 3$.