An image of a fish tank on a website is 10 cm wide and 6 cm long on the computer screen. The actual tank is 60 inches wide

1 inch = 2.54cm

6 x 10 = 60cm

60 x 2.54 = 152.4cm

152.4/ 60 = 2.54 -> Scale Factor

I don't know what you were supposed to work out, but here's some stuff I've worked out for you.

so, converting firstly the mixed fractions to improper fractions and then "adding".

ca = ec

cpctc makes it so that corresponding parts of the triangle you proved to be equal are equal, the other options aren't part of the part of the triangles you proved to be equal.