36 girls, 58 boys and 356 adults are members of a tennis club. 50 more children join the club. the number of girls is now 0.12 of the total number of members. how many of the 50 children were boys?

How to do this , and can some one explain

Find an equation of the line perpendicular to the graph of 28x-7y=9 that passes through the point at (4,1)

The bottom of ignacio's desktop is 74.5cm from the floor. ignacios sits in his adjustable chair, and the tops of his legs are 49.3cm from the floor. each clockwise rotation of the knob on the chair raises ignacio's legs by 4.8cm. write an inequality to determine the number of clockwise rotations, r, ignacio could make with the knob without his legs touching the desk.