World 7-4

Coin 1 (before checkpoint)

Bounce off the Banzai Bill at the end of the first section to grab this Star Coin.

Coin 2 (after checkpoint)

You'll find this Star Coin a short ways after the checkpoint. To grab it, leap from the middle platform while it's heading right and try to land on the platform below.

Coin 3 (after checkpoint)

Skip past the seemingly final red pipe (by the sign pointing up to it) to find another pipe high above. To reach it, you'll have to bounce off a Bullet Bill (remember to hold "up" as soon as you bounce off it to ensure you enter the pipe). After warping, head left to find the coin atop a pile of Bullet Bill launchers--just be careful of the bullets themselves! After grabbing it, you can reach the pipe on the right similar to the one before.