a)
[tex]v = \frac{1200}{69 \frac{45}{60} } = 1200 \div 69 \frac{45}{60} = 1200 \div \frac{4185}{60} = 1200 \times \frac{60}{4185} = \frac{72000}{4185} \approx17.2 \frac{km}{h} [/tex]
[tex] \boxed{ \boxed{Odp.B}}[/tex]
b)
[tex]127 \frac{20}{60} \div (5 \times 24) = \frac{7640}{60} \div 120 = \frac{7640}{60} \times \frac{1}{120} = \frac{7640}{7200} \approx1.06[/tex]
[tex] \boxed{ \boxed{Odp.D}}[/tex]
