New Super Mario Bros. - World 7-Ghost House

Reveal an orange switch from a block and press it to reveal 5 doors. Use the door at the top middle and ground pound through the yellow gel for the first Star Coin. Go back out and use the door on the middle left to find the 2nd Star Coin. Now use the door to enter a room with hands pointing at something. Hit an invisible block that reveals another orange switch and pressing the switch reveals a platform. Use the door at the top and hit the P Switch in the next room to harden the coins. Run as fast as you can by turning right and you’ll find the 3rd Star Coin at the dead end. Use the door to exit the mansion and you’ll find the goal.