An internet service provider charges ₱ 1.2 for the first minute and ₱ 0.8 per minute for subsequent minutes of a call. If duration of connection is represented as x, and amount charged is represented as y, find the linear equation for this relationship.

ABCD is a parallelogram with E and F as the mid-points of side AB and CD. Line segments CE and AF intersect the diagonal BD at point P and Q respectively. Find BD.

Two chords AB and AC of a circle subtends angles equal to 100º and 30º, respectively at the centre. Find ∠BAC, if AB and AC lie on the opposite sides of the centre.

In a class of 14 students, the average marks in a test was 63. If Lara got 65 marks and Marinka got 85 marks, what was the average of the other 12 students?