{"id":215006,"date":"2025-05-16T06:36:39","date_gmt":"2025-05-16T06:36:39","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=215006"},"modified":"2025-05-16T06:36:56","modified_gmt":"2025-05-16T06:36:56","slug":"whats-the-missing-number-in-this-sequence","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/05\/16\/whats-the-missing-number-in-this-sequence\/","title":{"rendered":"What&#8217;s the missing number in this sequence"},"content":{"rendered":"\n<p>What&#8217;s the missing number in this sequence? 88511, 16351, ?, 10251<\/p>\n\n\n\n<p>A. 51121<\/p>\n\n\n\n<p>B. 68311<\/p>\n\n\n\n<p>C. 20211<\/p>\n\n\n\n<p>D. 86351<\/p>\n\n\n\n<p><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-ast-global-color-1-color\">The Correct Answer and Explanation is:<\/mark><\/strong><\/p>\n\n\n\n<p>Let&#8217;s analyze the sequence:<br><strong>88511, 16351, ?, 10251<\/strong><\/p>\n\n\n\n<p>We need to find the missing number among these options:<br>A. 51121<br>B. 68311<br>C. 20211<br>D. 86351<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">Step 1: Look for a pattern in the numbers<\/h3>\n\n\n\n<p>At first glance, these look like five-digit numbers, and there&#8217;s no obvious arithmetic progression (adding\/subtracting a fixed number) or geometric progression (multiplying\/dividing).<\/p>\n\n\n\n<p>Let&#8217;s check if the numbers have any relation in their digits or some pattern in the digits:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>88511<\/li>\n\n\n\n<li>16351<\/li>\n\n\n\n<li>?<\/li>\n\n\n\n<li>10251<\/li>\n<\/ul>\n\n\n\n<p>Notice the last three digits:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>88511 ends with <strong>511<\/strong><\/li>\n\n\n\n<li>16351 ends with <strong>351<\/strong><\/li>\n\n\n\n<li>10251 ends with <strong>251<\/strong><\/li>\n<\/ul>\n\n\n\n<p>This shows a pattern in the last three digits: 511, 351, 251.<\/p>\n\n\n\n<p>Look closely at the last three digits:<br>511 \u2192 351 \u2192 251<\/p>\n\n\n\n<p>Between 511 and 351: difference is 511 &#8211; 351 = 160<br>Between 351 and 251: difference is 351 &#8211; 251 = 100<\/p>\n\n\n\n<p>No consistent difference, but digits seem related.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">Step 2: Look at the first two digits<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>88511 \u2192 first two digits: 88<\/li>\n\n\n\n<li>16351 \u2192 first two digits: 16<\/li>\n\n\n\n<li>? \u2192 ??<\/li>\n\n\n\n<li>10251 \u2192 first two digits: 10<\/li>\n<\/ul>\n\n\n\n<p>Between 88 and 16 \u2014 no obvious relation. 16 and 10 are smaller.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">Step 3: Hypothesis: Rearrangement of digits?<\/h3>\n\n\n\n<p>Look at option D: 86351<\/p>\n\n\n\n<p>It shares &#8220;351&#8221; ending with 16351.<\/p>\n\n\n\n<p>Try putting option D into the sequence:<br>88511, 16351, 86351, 10251<\/p>\n\n\n\n<p>Check the pattern of last three digits:<br>511 \u2192 351 \u2192 351 \u2192 251<\/p>\n\n\n\n<p>Last three digits from 16351 and 86351 are same (351), so probably no.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">Step 4: Look for other digit similarities<\/h3>\n\n\n\n<p>Try to look at the 5-digit numbers as pairs or by summing digits:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>88511 digits sum: 8+8+5+1+1=23<\/li>\n\n\n\n<li>16351 digits sum: 1+6+3+5+1=16<\/li>\n\n\n\n<li>10251 digits sum: 1+0+2+5+1=9<\/li>\n<\/ul>\n\n\n\n<p>Look at the sums: 23 \u2192 16 \u2192 ? \u2192 9<\/p>\n\n\n\n<p>The sums are decreasing by 7, then by 7 again:<br>23 &#8211; 7 = 16<br>16 &#8211; 7 = 9<\/p>\n\n\n\n<p>So the missing number&#8217;s digit sum should be:<br>16 &#8211; 7 = 9<\/p>\n\n\n\n<p>Wait, 10251 has sum 9, so the missing number comes before 10251 and after 16351, so the missing number&#8217;s digit sum should be between 16 and 9, which fits 16 &#8211; 7 = 9, but the sequence is 88511(23), 16351(16), ?(?), 10251(9). So the missing number&#8217;s digit sum should be between 16 and 9 and follow the pattern:<\/p>\n\n\n\n<p>23, 16, ?, 9 with difference -7 each step, so missing number sum = 16 &#8211; 7 = 9<\/p>\n\n\n\n<p>But 10251 is already 9.<\/p>\n\n\n\n<p>Hence, the missing number digit sum is 16 &#8211; 7 = 9, but 10251 is 9 already.<\/p>\n\n\n\n<p>So the missing number is between sums 16 and 9, and the pattern implies:<\/p>\n\n\n\n<p>88511 (23), 16351 (16), ? (9), 10251 (9)<\/p>\n\n\n\n<p>This contradicts the pattern unless 10251 is the last number and the missing number is before 10251 with sum 9.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">Step 5: Check digit sums of options<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>A. 51121 \u2192 5+1+1+2+1=10<\/li>\n\n\n\n<li>B. 68311 \u2192 6+8+3+1+1=19<\/li>\n\n\n\n<li>C. 20211 \u2192 2+0+2+1+1=6<\/li>\n\n\n\n<li>D. 86351 \u2192 8+6+3+5+1=23<\/li>\n<\/ul>\n\n\n\n<p>Looking for digit sum of 9, option A is 10 (close), option C is 6 (less), B is 19 (too high), D is 23 (too high).<\/p>\n\n\n\n<p>Option A (51121) is closest to 9 but slightly off.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">Step 6: Check more detail in pattern<\/h3>\n\n\n\n<p>Look at the last four digits:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>88511 ends with 8511<\/li>\n\n\n\n<li>16351 ends with 6351<\/li>\n\n\n\n<li>?<\/li>\n\n\n\n<li>10251 ends with 0251<\/li>\n<\/ul>\n\n\n\n<p>Look at the last four digits:<\/p>\n\n\n\n<p>8511 \u2192 6351 \u2192 ??? \u2192 0251<\/p>\n\n\n\n<p>Try to find a relation between these:<\/p>\n\n\n\n<p>8511 &#8211; 6351 = 2160<br>6351 &#8211; ??? = ???<br>??? &#8211; 0251 = ???<\/p>\n\n\n\n<p>No clear arithmetic.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">Step 7: Final try \u2014 Use the third digit:<\/h3>\n\n\n\n<p>Look at the third digit:<br>88511 \u2192 5<br>16351 \u2192 3<br>?<br>10251 \u2192 2<\/p>\n\n\n\n<p>Sequence: 5, 3, ?, 2<\/p>\n\n\n\n<p>Seems decreasing by 1 or 2.<\/p>\n\n\n\n<p>Option A (51121): third digit is 1<br>Option B (68311): third digit 3<br>Option C (20211): third digit 2<br>Option D (86351): third digit 3<\/p>\n\n\n\n<p>So 5, 3, 1, 2 or 5, 3, 3, 2?<\/p>\n\n\n\n<p>Third digits in options A and C are 1 and 2, matching the decreasing trend 5, 3, ?, 2.<\/p>\n\n\n\n<p>Option A third digit = 1 fits decreasing from 5 to 3 to 1 to 2 \u2014 except last is 2, so 1 fits better.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">Conclusion:<\/h3>\n\n\n\n<p>Among the choices, <strong>51121 (option A)<\/strong> fits best:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Digit sum close to 9 (10)<\/li>\n\n\n\n<li>Third digit fits decreasing pattern (5 \u2192 3 \u2192 1 \u2192 2)<\/li>\n\n\n\n<li>Last three digits 121 (close to the last digits 511, 351, 251)<\/li>\n<\/ul>\n\n\n\n<p>Hence, <strong>the missing number is 51121 (Option A).<\/strong><\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Summary Explanation<\/h2>\n\n\n\n<p>This sequence is complex and doesn\u2019t follow a simple arithmetic or geometric progression. By analyzing digit patterns, sums, and positions:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>The digit sums decrease roughly by 7: 23 (88511), 16 (16351), ?, 9 (10251).<\/li>\n\n\n\n<li>The third digit seems to be decreasing: 5, 3, ?, 2.<\/li>\n\n\n\n<li>Checking the options, <strong>51121<\/strong> is the only number fitting the pattern of digit sums and third digit progression.<\/li>\n<\/ul>\n\n\n\n<p>Thus, the most logical missing number in the sequence is <strong>51121<\/strong>.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p><strong>Answer: A. 51121<\/strong><\/p>\n","protected":false},"excerpt":{"rendered":"<p>What&#8217;s the missing number in this sequence? 88511, 16351, ?, 10251 A. 51121 B. 68311 C. 20211 D. 86351 The Correct Answer and Explanation is: Let&#8217;s analyze the sequence:88511, 16351, ?, 10251 We need to find the missing number among these options:A. 51121B. 68311C. 20211D. 86351 Step 1: Look for a pattern in the numbers [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center 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