1) \(1 \frac{2}{3} \cdot 1 \frac{1}{4} = \frac{5}{3} \cdot \frac{5}{4} = \boxed{\frac{25}{12} = 2 \frac{1}{12}}\)
2) \(N \cdot \frac{3}{8} = \frac{5}{3}\)
To isolate N, multiply both sides by the reciprical of 3/8, which is 8/3.
\(N = \frac{5}{3} \cdot \frac{8}{3} = \boxed{\frac{40}{9}}\)
3) \(2 \frac{3}{4} \div \frac{1}{8} = 2 \frac{3}{4} \cdot 8 = \frac{11}{4} \cdot 8 = \boxed{22}\)
4) \(\text{cashew nuts mass}= \frac{2}{5} \cdot 2 \frac{1}{2} = \frac{2}{5} \cdot \frac{5}{2} = 1\)
\(\text{total mass} = 2 \frac{1}{2} + 1 = 3 \frac{1}{2} = \frac{7}{2}\)
\(\text{mass per packet} = \frac{7/2}{8} = \boxed{\frac{7}{16}}\)
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