Blue cassettes hold 45 minutes of music. Green cassettes hold 55 minutes of music. if niko has 14 cassettes containing 710 minute of music, how many are blue, and how many are green

b + g = 14 (where b and g are no. of blue and green cassettes)

45b + 55g = 710

from first equation b = 14 - g so

45 (14 - g) + 55g = 710

630 - 45g + 55g = 710

10g = 80

g = 10 so b = 14-8 = 6

There are 6 blue and 8 green cassettes