Zumbara Math Challenge

Long ago at Fazenda da Toca, the capybaras lived peacefully by the lake — until a nuclear plant poisoned the water, a radioactive spider bit one of them, and she became Zumbara, the dreaded zombie capybara. At dusk, if you whisper her name, she stirs.

You have 60 seconds. Each math statement is either TRUE or FALSE. Correct answers give +1 s, wrong answers cost −1 s. Survive as long as you can.