Does anyone know how to do these maths

I'm confused on this could anyone me and show me what i need to do to solve it.

Merrida uses a pattern in the multiplication table below to find ratios that are equivalent to 7: 9. if merrida multiplies the first term, 7, by a factor of 6, what should she do to find the other term for the equivalent ratio? multiply 9 by 1. multiply 9 by 6. multiply 9 by 7. multiply 9 by 9.

Nthe opening scene of the movie raiders of the lost ark, indiana jones replaces a golden statue with a bag of sand. the platform on which the statue is placed is designed to detect the mass of the statue. if the bag of sand has a different mass than the statue, then a mechanism triggers and destruction ensues. the density of gold is about 20\text{ g/cm}^320 g/cm 3 20, space, g, slash, c, m, start superscript, 3, end superscript. the density of sand can be estimated at 2.5\text{ g/cm}^32.5 g/cm 3 2, point, 5, space, g, slash, c, m, start superscript, 3, end superscript. the gold statue can be modeled as a cylinder with height 25\text{ cm}25 cm25, space, c, m and radius 8\text{ cm}8 cm8, space, c, m. in terms of \piπpi, what is the mass of sand indiana jones needs to avoid triggering the mechanism?