Question

It often took him half an hour to plan this program -> It used.../He used

Answer 1

It often took him half an hour to plan this program

-> It used to take him half an hour to plan this program

He used to spend half an hour planning this program

Answer 2

It often took him half an hour to plan this program

-> It used...to take him half an hour to plan this program

He used to spend half an hour to plan this program

Answer 3

It often took him half an hour to plan this program
-> It used to take him half an hour to plan this program.
Or: He used to spend half an hour planning this program.