Question

Proof read my answers please. MEDALS AND FAN AND TESTIMONIALS:)
A lot of national flags are made up of three hSince all the colors must be different, and given that there are t stripes,
5*4*3=60

∴Therefore 60 different 3 color flags can be designed using the 5 colors.

b. Since if the red strip is used it would have to be once,
60/5=12

∴Therefore 12 flags contained a red stripe.

c.
If the top can be identical to the bottom, then

5*4*5=120

Since there are 120 possibilities
120-60=60

∴Then there would be 60 extra possibilities compared to the first 60 possibilities.

Answer 1

A lot of national flags are made up of three horizontal stripes.
How many different three color flags (tricolors) can be designed using green, blue, red, yellow and black stripes if all three colours must be different?
How many of them contain a red stripe?
How many extra possibilities are there if the top colour can be the same as the bottom colour?

Answer 2

Above are the original questions.

Answer 3

I'd appreciate your insight and opinions:)

Answer 4

By the way this is the permutation and combination unit.

Answer 5

Any ideas?