If the degree measures of the angles of quadrilateral are `4x ,\ 7x ,\ 9x\ a n d\ 10 x ,` what is the sum of the measures of the smallest angle and largest angle? `140^0` (b) `150^0` (c) `168^0` (d) `180^0`

Explanation

As we konw that the sum of all angles of a quadrilateral is `360^@`

A.T.Q

`4x+7x+9x+10x=360^@`

`30x=360^@`

`x=12^@`

Now, the angles are `48^@,84^@,108^@ and 120^@`

So, sum of the smallest angle and the largest angle is `48^@+120^@=168^@`

Hence, option (C) is correct.