Actuary and trustee reports indicate the following changes in the PBO and plan assets of Mahomes Industries during $2024$:

Prior service cost at January $1,2024,$ from plan amendment at the beginning of $2021($amortization: $$20$ million per year$)$

$ $140$ million

Net loss$-$AOCI at January $1,2024($previous losses exceeded previous gains$)$

$ $880$ million

Average remaining service life of the active employee group $10$ years

Actuary's discount rate $7\%$

$\backslash$table$[[\backslash$table$[[\backslash$table$[[$ in millions$)],[$PBO$]]]],$Plan Assets$],[$Beginning of $2024,$$ $2,200,$Beginning of $2024,$$ $2,000],[$Service cost$,96,\backslash$table$[[$Return on plan assets, $8\%(10\%],[$expected$)]],160],[$Interest cost$,7\%,154,,],[$Loss $($gain$)$ on PBO,$(30),$Cash contributions,$106],[$Less: Retiree benefits,$(70),$Less: Retiree benefits,$(70)],[$End of $2024,$$ $2,350,$End of $2024,$$ $2,196]]$

Required:

$1-$a$.$ Determine Mahomes's pension expense for $2024.$

$1-$b$,2.$ to $4.$ Prepare the appropriate journal entries to record the pension expense, to record any $2024$ gains and losses, to record the cash contribution to plan assets and to record retiree benefits.