{"id":"cb_question_bank:ac35345f-4ccc-4638-866d-3bef00c963c4","source_id":"cb_question_bank","source_item_id":"ac35345f-4ccc-4638-866d-3bef00c963c4","external_id":null,"ibn":"025772-DC","question_id":"e1391dd6","program":"SAT","module":"math","domain_code":"P","domain":"Advanced Math","skill_code":"P.C.","skill":"Nonlinear functions","difficulty":"M","score_band":4,"answer_type":"mcq","answer_source":"rationale","layout_warning":null,"form_id":null,"module_number":null,"position":null,"stem":"According to Moore’s law, the number of transistors included on microprocessors doubles every 2 years. In 1985, a microprocessor was introduced that had 275,000 transistors. Based on this information, in which of the following years does Moore’s law estimate the number of transistors to reach 1.1 million?","stimulus":"","stimulus_html":null,"stem_html":"<p class=\"stem_paragraph \">According to Moore’s law, the number of transistors included on microprocessors doubles every 2 years. In 1985, a microprocessor was introduced that had 275,000 transistors. Based on this information, in which of the following years does Moore’s law estimate the number of transistors to reach 1.1&nbsp;million? </p>\n","rationale_html":"<p>Choice B is correct. Let <span class=\"italic\">x</span> be the number of years after 1985. It follows that <span class=\"math-container\"><img align=\"middle\" role=\"math\" class=\"math-img\" src=\"/api/assets/a0af493c33c6c96f34aeb4458c5697e6328d618ea5c04f4ab1e64f67ba48dc5f\" alt=\"x over 2 \"></span> represents the number of 2-year periods that will occur within an <span class=\"italic\">x</span>-year period. According to Moore’s law, every 2 years, the number of transistors included on microprocessors is estimated to double. Therefore, <span class=\"italic\">x</span> years after 1985, the number of transistors will double <span class=\"math-container\"><img align=\"middle\" role=\"math\" class=\"math-img\" src=\"/api/assets/a0af493c33c6c96f34aeb4458c5697e6328d618ea5c04f4ab1e64f67ba48dc5f\" alt=\"x over 2 \"></span> times. Since the number of transistors included on a microprocessor was 275,000, or .275 million, in 1985, the estimated number of transistors, in millions, included <span class=\"italic\">x</span> years after 1985 can be modeled as <span class=\"math-container\"><img align=\"middle\" role=\"math\" class=\"math-img\" src=\"/api/assets/20ddfc0f8d6f4e94e0e818866d594e12957109d6870746b5f27ad98cfc8a93ac\" alt=\"0 point 2 7 5 times 2 raised to the x over 2 power\"></span>. The year in which the number of transistors is estimated to be 1.1 million is represented by the value of <span class=\"italic\">x</span> when <span class=\"math-container\"><img align=\"middle\" role=\"math\" class=\"math-img\" src=\"/api/assets/0d477011e515a67f14fde6dc9821b5216def696ff192d932d653f0035a1006dc\" alt=\"1 point 1 equals, 0 point 2 7 5, times 2 raised to the x over 2 power\"></span>. Dividing both sides of this equation by .275 yields <span class=\"math-container\"><img align=\"middle\" role=\"math\" class=\"math-img\" src=\"/api/assets/a2cf3a0b1c7dda3330597358ccb5d6e78965f4cd19c8f981754216844313b948\" alt=\"4 equals, 2 raised to the x over 2 power\"></span>, which can be rewritten as <span class=\"math-container\"><img align=\"middle\" role=\"math\" class=\"math-img\" src=\"/api/assets/52341e4f1ef9d599d85e59116de8f954c66854a85f30fb9b63f693264a2a9593\" alt=\"2 squared equals, 2 raised to the x over 2 power\"></span>. Since the exponential equation has equal bases on each side, it follows that the exponents must also be equal: <span class=\"math-container\"><img align=\"middle\" role=\"math\" class=\"math-img\" src=\"/api/assets/e921b49ce64a7322a45cb1db117ba00fab3593d995ccffa9d82577057487ca5f\" alt=\"2 equals x over 2\"></span>. Multiplying both sides of the equation <span class=\"math-container\"><img align=\"middle\" role=\"math\" class=\"math-img\" src=\"/api/assets/e921b49ce64a7322a45cb1db117ba00fab3593d995ccffa9d82577057487ca5f\" alt=\"2 equals x over 2\"></span> by 2 yields <span class=\"math-container\"><img align=\"middle\" role=\"math\" class=\"math-img\" src=\"/api/assets/7d90bc5cab99d91a4fc94163803642158e44f5a08bde8400e28498891da16def\" alt=\"x equals 4\"></span>. Therefore, according to Moore’s law, 4 years after 1985, or in 1989, the number of transistors included on microprocessors is estimated to reach 1.1 million.</p><p>Alternate approach: According to Moore’s law, 2 years after 1985 (in 1987), the number of transistors included on a microprocessor is estimated to be <span class=\"math-container\"><img align=\"middle\" role=\"math\" class=\"math-img\" src=\"/api/assets/5eca2f18117fdb7ee92c7d9da194c778459f930f352e9349dc8c984626dd047e\" alt=\"2 times 275,000\"></span>, or 550,000, and 2 years after 1987 (in 1989), the number of transistors included on microprocessors is estimated to be <span class=\"math-container\"><img align=\"middle\" role=\"math\" class=\"math-img\" src=\"/api/assets/1151600c251ef4c1b619cde7e31bb6f20d8ea9f9ae50007ea5ca2e62400ec18f\" alt=\"2 times 550,000\"></span>, or 1,100,000. Therefore, the year that Moore’s law estimates the number of transistors on microprocessors to reach 1.1 million is 1989.</p><p>Choices A, C, and D are incorrect. According to Moore’s law, the number of transistors included on microprocessors is estimated to reach 550,000 in 1987, 2.2 million in 1991, and about 6.2 million in 1994.</p><p></p>\n","correct_answer":["B"],"has_media":true,"has_mathml":false,"has_table":false,"source_created_at":"2023-08-02T20:25:59.619000+00:00","source_updated_at":"2023-08-02T20:25:59.619000+00:00","options":[{"label":"A","content_html":"<p class=\"choice_paragraph \">1987</p>\n","ord":0},{"label":"B","content_html":"<p class=\"choice_paragraph \">1989</p>\n","ord":1},{"label":"C","content_html":"<p class=\"choice_paragraph \">1991</p>\n","ord":2},{"label":"D","content_html":"<p class=\"choice_paragraph \">1994</p>\n","ord":3}],"attribution":{"source_id":"cb_question_bank","source_name":"College Board digital SAT question bank (community dump)","rights_holder":"College Board","canonical_url":"https://satsuitequestionbank.collegeboard.org/","retrieved_from":"https://raw.githubusercontent.com/mdn522/sat-question-bank/main/data/cb-digital-questions.json","attribution":"SAT practice questions © College Board, from the official SAT Suite Question Bank. Retrieved via the community dump at github.com/mdn522/sat-question-bank.","disclaimer":"SAT® and PSAT/NMSQT® are trademarks registered by the College Board, which is not affiliated with, does not sponsor, and does not endorse this project.","license":"College Board copyright; source repository carries no licence. Local use only.","redistributable":false,"item_count":2017}}