50 ml of water is poured into a beaker. 50 ml of another liquid is poured into the same beaker. The beaker is left undisturbed for some time. After some time, it is observed that the liquid forms a clear layer on top of water. If the density of water is 1 g/cc, what could be the density of the second liquid?

Prove that the value of the expression 7^8–7^7+7^6 is divisible by 43.

If the sales price of a dvd is $20 and the markup is 34%, what is the cost of the dvd?

Assume that there is a 11% rate of disk drive failure in a year. a. if all your computer data is stored on a hard disk drive with a copy stored on a second hard disk drive, what is the probability that during a year, you can avoid catastrophe with at least one working drive? b. if copies of all your computer data are stored on four independent hard disk drives, what is the probability that during a year, you can avoid catastrophe with at least one working drive?