randRange(1, 8) randRange(A + 1, 9)
randRange(1, 8) randRange(C + 1, 9)

\dfrac{A}{B} \times \dfrac{C}{D}

(A * C) / (B * D)

= \dfrac{A \times C}{B \times D}

= \dfrac{A * C}{B * D}

= fractionReduce(A * C, B * D)