It is 70% Because:
250/100 + 175/x
Proportions
The <em>correct answer</em> is:
Independent.
Explanation:
The criteria for binomial experiments are:
A fixed number of trials.;
Each trial is independent of the others.;
There are only two outcomes; and
The probability of each outcome remains constant from trial to trial.
This means the outcomes are constant and independent.
What vectors? do you have more info?