6) If 5 kg of a substance is reduced to 2 kg in one hour, when was half of it decomposed?

a) 0.86 hr

b) 0.76 hr

c) 0.66 hr

d) 0.56 hr

7) Find the area bounded by y = √ 9 - x, x = 5, x = 8 and y = 0.

a) 14/3

b) 13/3

c) 11/3

d) 10/3