A grid is built from rods and straws: the rods run one way and the straws run across them, so a grid m sections long and n sections wide needs a full line of straws down each of the m+1 divisions and a full line of rods across each of the n+1 divisions. (a) How many rods and straws altogether are used for a grid 3 rods long and 4 straws wide? (b) How many for a grid 4 long and 52 wide?
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