Milan's Coffee Shop makes a blend that is a mixture of two types of coffee. Type A coffee costs Milan $5.10 per pound, and type B coffee costs $4.05 per pound. This month's blend used four times as many pounds of type B coffee as type A, for a total cost of $489.90. How many pounds of type A coffee were used?
Number of pounds of type A coffee:

answer:   35 % is the probability of a late departure or an early arrival.

step-by-step explanation:

let l represents the late departure and e represents the early departure.

then, according to the question,

p(l) = 12 %,   p(e) = 27 % and = 4 %

and, we have to find out,

but, we know that,

which is the required equation that will use to find the probability of a late departure or an early departure.

therefore,   the probability of a late departure or an early arrival =   35 %