Help me pleasee I’m not sure I’m doing theses correctly ?

In the image, point a marks the center of the circle. which two lengths must form a ratio of 1 : 2? (options are in the images since thought they were harmful phrases)

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.

If the regular price was $115, how much did jeanine pay for the hiking boots? jeanine bought a new pair of hiking boots on sale for 25% off the regular price. enter the correct answer. ooo done clestall the following formula describes this scenario: đoo s = r. 0.25 r = regular price s = sale price