20% off means it is selling for 80% of the original price ( 100% - 20% =80%)
Divide the sale price by 80% as a decimal:
380/0.80 = 475
The original price was $475
Justify:
Multiply the original price by 20% and subtract:
475 x 0.20 = 95
475-95 = $380 which is the sale price.
A) Yes, the two events are independent because P(NF|PB) = P(NF).
5 -> 15
6 -> 20
7 -> 25
8 -> 30
9 -> 35
10 -> 40
then in ones:
after 41 would be 42 and 43
the elapsed time would be 43 minutes :)
hope this helps :)
I think the answer is C 1 2/3