A board 1.2m long is cut so the length of the longer piece is 15cm longer than twice the length of shorter piece.How long is the shorter piece?

1.2 m = 120 cm

Let the shorter piece be x, then the longer piece is 2x + 15. So we have:

x + 2x + 15 = 120

3x + 15 = 120 subtract 15 to both sides

3x = 105 divide by 3 to both sides

x = 35

Thus the shorter piece is 35 cm.