The ratio of two number is 5: 3 the sum of the number is 16 what are the numbers

Alicia puts $400 in a bank account. each year the account earns 5% simple interest. how much money will be in her bank account in six months?

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.

What is the measure of ac? 5 units 13 units 26 units 39 units 3x- 2b 6x + 9