DUE 14th Sept - Thanks and please show working out

Bryn has a stack of photos measuring 12 cm wide and 16 cm high. He wants to display them on a large rectangular poster in such a way that all photos are equally spaced on each side, including at the edges of the poster as illustrated.

*NOT TO SCALE* (The black squares are one *photo* and the photos are separated by arrows)

↑ ↓ ↑ ↓
←→ ■■■ ←→. ■■■ ←→

←→ ■■■ ←→ ■■■ ←→
↑ ↓. ↑ ↓


Please solve the below questions


a) Bryn wants to display 24 photos (with longer side vertical) with 2 cm spacing around each photo. He wants more columns than rows of photos. Find the smallest poster area that is needed.


B) Bryn wants to display 18 photos in 3 rows of 6 photos each with 3 cm spacing around each photo. The photos may all be displayed in portrait orientation or landscape. Which orientation uses less poster area?


C) Bryn wants to display 24 photos with longer side verticals in 6 rows of 4 photos with equal spacing around each photo. He has a poster that is 62cm wide and 120 cm high. He wants to use the full width of the poster but is prepared to trim the height to achieve equal spacing. How much of the poster does he need to trim?