Numerele a si b sunt invers proportinale cu 6 si 15. Cat la suta din a reprezinta b?

[tex]6a = 15b = k = > \\ a = \frac{k}{6} \\ b = \frac{k}{15} [/tex]

[tex] \frac{a}{b} = \frac{ \frac{k}{6} }{ \frac{k}{15} } = \frac{k}{6} \div \frac{k}{15} = \frac{k}{6} \times \frac{15}{k} = \frac{5}{2} [/tex]

[tex] \frac{a}{b} = \frac{5}{2} = \frac{5 \times 20}{2 \times 20} = \frac{100}{40} [/tex]

=> b=40% din a