{"id":"cb_practice_pdf:t7-math-m2-q15","source_id":"cb_practice_pdf","source_item_id":"t7-math-m2-q15","external_id":null,"ibn":null,"question_id":null,"program":"SAT","module":"math","domain_code":null,"domain":null,"skill_code":null,"skill":null,"difficulty":null,"score_band":null,"answer_type":"mcq","answer_source":"rationale","layout_warning":"Part of this question was typeset outside the text flow — a fraction, subscript or similar — and PDF extraction re-inserted it in the wrong place. The wording is reliable; the symbols may be out of order.","form_id":"cb_practice_pdf:test-7","module_number":2,"position":15,"stem":"An investment account was opened with an initial $890 value of. The value of the account doubled every 10 years. Which equation represents the value of the account M(t), in dollars, t years after the account was opened? t  ^10 = 890  ","stimulus":"","stimulus_html":null,"stem_html":"<p>An investment account was opened with an initial $890 value of. The value of the account doubled every 10 years. Which equation represents the value of the account M(t), in dollars, t years after the account was opened? t  ^10 = 890  </p>","rationale_html":"<p>Choice C is correct. It’s given that t represents the number of years since the 10 account was opened. Therefore, 1t0 represents the number of -year periods since the account was opened. Since the value of the account doubles during 10 each of these -year periods, the value of the account can be found by multiplying the initial value by 1t0 factors of 2. This is equivalent to 21t0 . It’s given $890 that the initial value of the account is . Therefore, the value of the account M^th, in dollars, t years after the account was opened can be represented by =890 2 1t0 M^th ^ h . Choice A is incorrect. This equation represents the value of an account if the 10 value of the account halves, not doubles, every years. Choice B is incorrect. This equation represents the value of an account if the value of the account 90% 10 decreases by , not doubles, every 2, not , years. Choice D is incorrect. This equation represents the value of an account if the value of the account increases 10 10 by a factor of , not doubles, every 2, not , years.</p>","correct_answer":["C"],"has_media":false,"has_mathml":false,"has_table":false,"source_created_at":null,"source_updated_at":null,"options":[{"label":"A","content_html":"<p>M ( t )   1/2    t  ^2 = 890  </p>","ord":0},{"label":"B","content_html":"<p>M ( t )   1/10    10 = 890 2</p>","ord":1},{"label":"C","content_html":"<p>M ( t ) ( )^t 2 M ( t ) = 890 ( 10 )^t</p>","ord":2},{"label":"D","content_html":"","ord":3}],"attribution":{"source_id":"cb_practice_pdf","source_name":"College Board full-length SAT practice tests (PDF)","rights_holder":"College Board","canonical_url":"https://satsuite.collegeboard.org/practice/practice-tests/paper","retrieved_from":"https://satsuite.collegeboard.org/practice/practice-tests/paper","attribution":"Full-length SAT practice tests 4–11 © College Board, published free at satsuite.collegeboard.org.","disclaimer":"Extracted from PDF layout: equations, figures and tables do not survive intact. Use the original PDFs for anything the text renders poorly. SAT® is a trademark registered by the College Board, which is not affiliated with and does not endorse this project.","license":"College Board copyright. Free to download; not licensed for redistribution.","redistributable":false,"item_count":905}}