Explanation : (A) Given, ABCD is a cyclic quadrilateral we know that sum of opposite angles of a cyclic quadrilateral is 180o.
4x + 4y + 20 = 180
4x + 4y = 160
⇒ x + y = 40 .......(i)
and (7x + 5) + (3y - 5) = 180o
⇒ 7x + 3y = 180 ....... (ii)
On solving Eqs. (i) and (ii), we get,
x = 15o and y = 25o
Explanation : (A) We know that mode is the value of the observation which occurs most frequently from question, occurrence of 25= 3
occurrence of 26 = 3 and occurrence of 27 = 3
Since mode of following data is 27.
So, value of x is 27.