Where x is the length of the first piece

so the first piece is 3 inches, the second is 6 inches and the third is 19 inches
Let x be the number of running plays
Y be the number of
passing plays
Since the total plays is 110
X + y = 110
And total yard is 378
3x + 7y = 378
Using the first equation
X = 110 – y and substitute to the 2nd equation
3(110 – y) + 7y = 378
And solve for y
Y = 12
Substitute to eqution 1
X = 110 – 12 = 98
4. 15 tens, 1 hundred, 5 tens
150
5. 18 tens, 1 hundred, 8 tens
180
note: I hope this helps. I haven't done this in a long time. Sorry X(