If a penny is tossed five times, what is the probability of all tails? a zero b 1/16 c 1/32 d larger than the probability of all heads

answer

the correct answer is the second option

explanation

given the two equations;

and

we can either decide to eliminate or .

if we want to eliminate , then we need to make the coefficients of

in both equations the same.

the coefficient of in equation (2) is and that of equation (1) .

so we multiply equation (1) by and equation (2) by .

now that the coefficients are the same, subtracting the two equations will eliminate from the equation.

also, multiplying the first equation by 2 and the second equation by 9, and then subtract will eliminate

therefore the correct option is b.

note option c will not eliminate , when we add. that makes it incorrect.