Can someone help me solve? Simplify each expression show work

At least two people have the same birthday in a school of 150 students

What is true about the dilation? it is a reduction with a scale factor between 0 and 1. it is a reduction with a scale factor greater than 1. it is an enlargement with a scale factor between 0 and 1. it is an enlargement with a scale factor greater than 1.

Acomputer store buys a computer system at a cost of $370.80. the selling price was first at $ 618, but then the store advertised a 20 % markdown on the system. answer parts a and b. a. find the current sale price.