3 / 3/5 × 4 / 3/4 = ?
3 / 3/5 = 3 * 5/3 = 5
4 / 3/4 = 4 * 4/3 = 16/3
so
3 / 3/5 × 4 / 3/4
= 5 * 16/3
= 80/3
= 26 2/80
= 26 1/40