I need someone who is really good at questions like this! It is really important! Sorry for the quality!

2 yellow pebbles

lol thats was fun.

basically a green pebble equals 3 red pebbles and 3 red pebbles equals 9 yellow pebbles (because a red pebble equals 3 yellow pebbles)

so keep in mind i simplified the one green pebble eventually equals to 9 yellow pebbles

now a blue pebble is equal to a red pebble and 2 yellow pebbles

we know a red pebble is 3 yellow pebbles so we add the 3 and 2 yellow pebbles to get 5 yellow pebbles

now because it says "a green pebble and a blue pebble divides" you add the 9 and 5 yellow pebbles to get 14 pebbles

then it says "divide by 2 red pebbles and a yellow pebble"

2 red pebbles equals 6 yellow pebbles

6 yellow pebbles plus one yellow pebble is 7 pebbles

now we got all we need...

14 yellow pebbles ÷ 7 yellow pebbles

EQUALS

2 yellow pebbles

HOPE THIS HELPS YE

answer; /// the correct answer is (a) burned the city;

to stay where they were until m sent for