You climb a spiral of floating steps, each labelled with a letter: A… C… F… J… The steps ahead are missing, suspended in darkness. Only by naming the next stone will the path appear beneath your feet.
Question:
Complete the sequence: A=1, C=3, F=6, J=10, ?
Hint: From J, take five hops forward; for the number, add five to 10. If you still need help after this, I’m sending you a sympathy biscuit.