There were a total of 8 football games a month, and 4 are played at night. The season is played for 2 months. How many football games are in the seasons ?

Using only odd number for numerators write two different subtraction problems that have a difference of 3/4

Which expression represent a number that is one fourth as great as 10-2a. (10-2)+4b. (10-2)÷4c. (10-2)-4d. (10-2)×4

The life, in years, of a certain type of electrical switch has an exponential distribution with an average life b = 2. if 100 of these switches are installed in dif- ferent systems, what is the probability that at most 30 fail during the first year?