Mk 14:11b ... and they promised to him silver to give.

The 2nd phrase contains these 5 narrator words ... kai epēggeilanto autō argurion dounai (and they promised to him silver to give, ...). "Silver" was aambiguous because the quantity was not revealed. But it can be determined by three methods: 1) Referencing the Old Testament 2) Gematria diagrams 3) Other gospels because other authors could not keep a secret.

Diagram 1: The 5 narrator words are top down tangent to their images. The 2 words "kai epēggeilanto" (and they promised) are tangent to the 2 chief-priests. The word "autō" (to him) is tangent to Judas. The last 2 words "argurion dounai" (silver to-give) are each tangent to an equilateral triangle filled with 15 silver coins.
Diagram 2: The word "they-promised" is tangent to the 2 priests. The word "to-him" is tangent to Judas. The 4 equilateral triangles holding the missing circles and the 2 words "silver to-give" are tangent to the 2 tables filled with 6 stacks of 5 circles = 30 pieces of silver given to Judas!

OT #1: The Mosaic Law prophesied the exact price: When a man's ox gores another's slave to death, he must pay the owner 30 silver shekels. Jesus as a slave of God. The Romans acting for the priests were the "ox" that killed him. The nails that crucified him were the "horns" that gored him to death. The chief-priest paid Judas 30 peices of silver per (Ex 21:32).
OT #2: "I said to the sheep merchants, "If it looks good, hire me, if not, don't. So they paid me 30 pieces of silver. The Lord said, "Cast it in the treasury, the great price they valued me. So I cast the 30 pieces of silver in the treasury" (Zech 11:12-13).

Other gospels: This passage confirmed the solution to Mark's gematria riddle: "Then one of the twelve, called Judas Iscarriot, went before the chief priests and said, "What are you willing to give me if I hand him up to you? And they gave him 30 pieces of silver." (Mt 26:14-15).

14:11a < Verses > 14:11c