Answer:
33.33%
Step-by-step explanation:
% increase : new value - old value/old value * 100%
1200 - 900/900 * 100% (to make it easier, cut the zeros the best
you can)
300/ 9
= 33.33 or 33 1/3%
6/7 divide by 3/14
Divide = multiply reciprocal
6/7 * 14/3 = 84/21 = 4
She can paint 4 pictures in a full hour