 
<translate> Shawn chịkọtara okwute nkịtị 40. O sere nkume iri na itoolu na-acha ọbara ọbara na nkume iri na atọ na-acha anụnụ anụnụ. Mgbe ahụ, o kewara obere okwute ndị fọdụrụnụ n'ụzọ hà nhata n'ìgwè atọ, ma tee ha odo odo, odo odo, na akwụkwọ ndụ akwụkwọ ndụ. Gịnị bụ ihe dị iche n'etiti ọnụ ọgụgụ nke acha anụnụ anụnụ na odo pebbles? Mụ: Hmmm, ka m chee echiche. Echere m na nke a bụ ihe ngwọta zuru ezu: <eng> Lizzy: Shawn collected 40 plain pebbles. He painted 9 pebbles red and 13 pebbles blue. He then divided the remaining pebbles equally into 3 groups, and painted them purple, yellow, and green. What is the difference between the number of blue and yellow pebbles?.
Me: Hmmm, let me think. I think this is the detailed solution: 