Due to popular demand, the Khan Academy test-prep materials have been archived in the Kolibri Channel called "Khan Academy - Standardized Test Preparation" see https://kolibri-catalog-en.learningequality.org/en/learn/#/t...

If you want to continue accessing these, check out the instructions about setting up Kolibri posted in the thread above, then in step 3 download this channel using the token "nojon-baraz" or simply select from list. Once you download to localhost (might take a while), you'll have all the videos and exercises locally so not a problem even if this materials are taken down from the KA website.