Today 9*( 1+ 10%)=9.9.

autumn

Range (9.9-10)/10 *100% =-1%, decrease1%.

2 The maximum diameter of the round table is 8 decimeters = 0.8m r=0.4 s=0. 16π.

(0.8-0. 16π)/0.8=

3 plan a

0.6a in the first half and 0.55a in the second half.

0.6a+0.55a=300+a