Question

please say the correct answer​

Answer 1

Answer:

Mean score = Σ fi xi/ Σ fi

20 = [(295 + (20 + p) 5p)]/ 15 + 5p

295 + 100 p + 5p2 = 300 + 100p

5p2 = 300 – 295 5p2= 5

p2 = 1

p = 1

Answer 2

Answer:

Step-by-step explanation:

Destructive distillation of coal is carried out by heating coal strongly to 1000 °C in the absence of air. It yields various useful organic and inorganic products. ... Coal tar: used to make pesticides, explosives, perfumes, etc. Ammonium compounds: making nitrogenous fertilizers.