Regina had 30 m of ribbon. She gave 2.7 m of the ribbon to each of her 4 friends and used the rest to decorate some presents for a party. 70 cm of ribbon were needed to decorate each presents. Find the most number of presents she could decorate.
Regina gave a total of 2.7 m x 4 = <<2.7*4=10.8>>10.8 m of ribbon to her friends.
She used 10.8 m of ribbon leaving her with 30 m - 10.8 m = <<30-10.8=19.2>>19.2 m of ribbon to decorate the presents.
There are 100 cm in 1 m, so 30 m is equal to 30 m x 100 cm = <<30*100=3000>>3000 cm.
Thus, Regina can decorate 3000 cm / 70 cm/present = <<3000/70=42.857142857142854>>42.86 or 42 presents.
Therefore, the most number of presents she could decorate is 42. Answer: \boxed{42}.