How would i work out:

bianca holds out a sack of counters.
3 are red
7 are blue
the rest are yellow.

her friend adore takes a random counter out.
the probability that she takes a yellow is 2/7.
how many yellow counters are in bianca's sack?

Although changes result from business transactions, the equality of the fundamental bookkeeping equation must remain. t/f

Aline passes through 3,7 and 6,9 what equation represents the line

Data from 2005 for various age groups show that for each $100 increase in the median weekly income for whites, the median weekly income of blacks increases by $105. also, for workers of ages 25 to 54 the median weekly income for whites was $676 and for blacks was $527. (a) let w represent the median weekly income for whites and b the median weekly income for blacks, and write the equation of the line that gives b as a linear function of w. b = (b) when the median weekly income for whites is $760, what does the equation in (a) predict for the median weekly income for blacks?