You will need 62 square inches of red paint to cover the entire block.
Explanation: 10+10+15+15+6+6=62
To find the surface area you have to calculate the area of each side and then add them up. The block has six sides. Two sides with an area of 2x5=10
Two sides with an area of 3x5=15
And two sides with an area of 2x3=6