Ineed with these two problems

19. in a store, 1 can of soup
costs $1.80. the store also sells a pack of 6 cans of the soup. a customer who buys 1 pack saves 15% compared to buying 6 cans separately. how much money does a customer save by buying 1 pack instead of buying 6 cans separately?

The magnitude, m, of an earthquake is defined to be m=log l/s, where i is the intensity of the earthquake (measured by the amplitude of the seismograph wave) and s is the intensity of a “standard” earthquake, which is barely detectable. what is the magnitude of an earthquake that is 1,000 times more intense than a standard earthquake? use a calculator. round your answer to the nearest tenth.

Offering 30 if a plus b plus c equals 68 and ab plus bc plus ca equals 1121, where a, b, and c are all prime numbers, find the value of abc. the answer is 1978 but i need an explanation on how to get that.

Are the corresponding angles congruent? explain why or why not.