D and E are points on side AB and AC of ΔABC. DE is parallel to BC. If AD:DB = 2:5 and area of ΔABC is 98 cm sq, what is the area (in sq cm) of quadrilateral BDEC?
The arithmetic mean of the marks scored by students of a class is 58. 20% of them secured a mean score of 60. The mean score of another 30% of the students was 40. The mean score of the remaining students is