PLEASE HELP B$-$F$!$ A$=100$ kPa!!!

Refer to the given element of soil with applied stresses as indicated in the figure below for $6$ a through $6f.$

a$.$ Determine the major principal stress $({}_1)($in units of kPa $).$ ANSWER$=100$kPa

b$.$ Find the minor principal stress $({}_3)($in units of kPa $).$

c$.$ Find the normal stress $({}_{})$ acting on a plane inclined $30$ degrees counter$-$clockwise from the horizontal $($in units of kPa $).$

d$.$ Find the shear stress $({}_{})$ acting on a plane inclined $30$ degrees counter$-$clockwise from the horizontal $($in units of kPa $).$

e$.$ Find the maximum shear stress $({}_{\text{m}\text{a}\text{x}})$ acting within the specimen $($in units of kPa $).$

f$.$ Determine the inclination of the plane that the maximum shear stress acts on in degrees from the horizontal $($inclination from the horizontal$).$