$($Take account of bid$-$ask spreads in this question.$)$ Still at Deutsche, you see a broker is

quoting the following spot rates:

EUR$-$USD: $0\mathrm{.}9170-75$

USD$-GBP$: ${1\mathrm{.}2690}_{95}$

a$)$ What do these quotes mean?

b$)$ What is the implied EUR$-$GBP two$-$way cross rate?

c$)$ You call a Frankfurt bank and ask for the spot EUR$-$GBP cross rate. You hope to

make a profitable triangular arbitrage. What two$-$way quotes would allow you to do

this? Give some examples.