An English teacher would like to divide 15 boys and 20 girls into groups, each with the same combination of boys and girls and nobody left out. What is the greatest number of groups that can be formed?

Right ∆abc has coordinates a(-7, 3), b( -7, 10), and c(-1, 3). the triangle is reflected over the x - axis and then reflected again over the y - axis to create ∆a'b'c'. which are the coordinates of vertex a'?