Which fraction has a terminating decimal as it's decimal expansion? - 1/3 - 1/5- 1/7 - 1/9

The mean of a set of data is -3.82 and its standard deviation is 2.31. find the z score for a value of 3.99.

What are the measures of ∠a, ∠b, ∠c and ∠d? explain how to find each of the angle measure.

Prove that the sum of two consecutive exponents of the number 5 is divisible by 30.if two consecutive exponents are 5n and 5n + 1, then their sum can be written as 30.