the probability that an imdividual is left-handed is 0.30 in a class of 25 students, what is the the mean and standard deviation of the number of left-handers in the class

Mean = np = 25 * .3 = ?

Standard deviation = √npq = √(25)(.3)(.7) = ?
Note: q = 1 - p

I'll let you finish the calculations.