[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"doc-detail-207758-en":3,"doc-seo-207758-105":30,"detail-sidebar-cat-0-en-105":83},{"code":4,"msg":5,"data":6},0,"success",{"doc_id":7,"user_id":8,"nickname":9,"user_avatar":10,"doc_module":4,"category_id":11,"category_name":12,"doc_title":13,"doc_description":14,"doc_content":15,"file_id":16,"file_url":17,"file_type":18,"file_size":19,"view_count":20,"is_deleted":4,"is_public":20,"is_downloadable":20,"audit_status":20,"page_count":21,"language":22,"language_code":23,"site_id":24,"html_lang":23,"table_of_contents":25,"faqs":26,"seo_title":27,"seo_description":14,"update_tm":28,"read_time":29},207758,687207024478,"Mia  ","https://ap-avatar.wpscdn.com/davatar_a8503ba1806abce46bf441b54a3ca4cd",4,"Exam","Simple, Compound Interest, Depreciation, Growth & Decay (H) - Maths GCSE Sample Questions","A set of 9-13 maths GCSE-style sample and specimen questions focused on exponential and compound processes. Topics include bacteria halving and quarter reduction with standard form answers, car value given by an exponential decay model, and compound interest across multiple years with an unknown rate. Additional tasks cover comparing growth rates using geometric progressions, population growth with percentage increases, and compound interest to find initial or final investment values. Further questions apply depreciation, percentage changes, and exponential recurrence models to real contexts such as viruses, city populations, slugs, and bees.","Simple, Compound Interest, Depreciation, Growth & Decay (H)  \nA collection of 9-1 Maths GCSE Sample and Specimen questions from AQA, OCR, Pearson-Edexcel and WJEC Eduqas.  \n\n| Name: |  |\n| --- | --- |\n| Total Marks: |  |\n\n1. (a) During an experiment, a scientist notices that the number of bacteria halves every second.  \nThere were 2∙3 × 1030 bacteria at the start of the experiment.  \nCalculate how many bacteria were left after 5 seconds.  \nGive your answer in standard form correct to two significant figures.  \n[3]  \n(b) In a different experiment the number of bacteria is reduced by a quarter each second. On this occasion the number of bacteria initially was x.  \nWrite a formula to calculate the number of bacteria, r, remaining after t seconds.  \n[3]  \n2. The value of a car £V is given by  \nV = 20 000 × 0.9t  \nwhere t is the age of the car in complete years.  \n(a) Write down the value of V when t = 0.  \n(a) £ ........................... [1]  \n(b) What is the value of V when t = 3?  \n(b) £ ........................... [ 2]  \n(c) After how many complete years will the car’s value drop below £10 000?  \n(c) .............................. [2]  \n3. Katy invests £2000 in a savings account for 3 years.  \nThe account pays compound interest at an annual rate of  \n2.5% for the first year  \nx% for the second year  \nx% for the third year  \nThere is a total amount of £2124.46 in the savings account at the end of 3 years. Work out the rate of interest in the second year.  \n....................................................... [4]  \n4. Louis and Robert are investigating the growth in the population of a type of bacteria. They have two flasks A and B.  \nAt the start of day 1, there are 1000 bacteria in flask A.  \nThe population of bacteria grows exponentially at the rate of 50% per day.  \n(a) Show that the population of bacteria in flask A at the start of each day forms a geometric progression.  \n[2]  \nThe population of bacteria in flask A at the start of the 10th day is k times the population of bacteria in flask A at the start of the 6th day.  \n(b) Find the value of k.  \n........................... ............................ [2]  \nAt the start of day 1 there are 1000 bacteria in flask B.  \nThe population of bacteria in flask B grows exponentially at the rate of 30% per day.  \n(c) Sketch a graph to compare the size of the population of bacteria in flask A and in flask B.  \n[1]  \n5. Here are the interest rates for two accounts.  \nDerrick has £10 000 he wants to invest.  \na) Calculate which account would give him most money if he invests his money for 3 years.  \nGive the difference in the interest to the nearest penny.  \na) [Account ................... by ................... p](Account ................... by ................... p) [5]  \n(b) Explain why he might not want to use Account A.  \n[1]  \n6. The population, P, of an island t years after January 1st 2016 is given by this formula.  \nP = 4200 × 1.04t  \na) What was the population of the island on January 1st 2016?  \n(a) ............................................ [1]  \nb) Explain how you know that the population is increasing.  \n[1]  \nc) What is the annual percentage increase in the population?  \nc) ........................................ %[ 1]  \nd) Work out the population of the island on January 1st 2021.  \nd) ............................................ [ 2]  \n7. Toby invested £7500 for 2 years in a savings account.  \nHe was paid 4% per annum compound interest.  \nHow much money did Toby have in his savings account at the end of 2 years?  \n£ ....................................................... [2]  \n8. Ibrar bought a house for £145 000  \nThe value of the house depreciated by 4% in the first year.  \nThe value of the house depreciated by 2.5% in the second year.  \nIbrar says,  \n“4 + 2.5 = 6.5 so in two years the value of my house depreciated by 6.5%”  \na) Is Ibrar right?  \nYou must give a reason for your answer.  \n[2]  \nThe value of Ibrar’s house increases by x% in the third year.  \nA","cbCaibCgkcPGo6eY","https://ap.wps.com/l/cbCaibCgkcPGo6eY","pdf",447799,1,8,"English","en",105,"# Simple and compound interest\n## Bacteria halving and quarter reduction\n## Car value decay model\n## Savings interest with changing rates\n# Exponential growth and comparisons\n## Geometric progression in bacterial flasks\n## Compare two exponential growth populations\n## Island population growth from a formula\n# Depreciation and compound interest in scenarios\n## House depreciation and recovery growth\n## Identify initial investment from compound interest\n## Account choice using interest differences","[{\"question\":\"What is tested in the depreciation and interest questions?\",\"answer\":\"They check correct compounding and how to interpret percentage changes across time.\"}]","Simple, Compound Interest, Depreciation, Growth & Decay (H) - Maths GCSE Sample Questions | PDF",1788601067,20,{"code":4,"msg":31,"data":32},"ok",{"site_id":24,"language":23,"slug":33,"title":13,"keywords":34,"description":14,"schema_data":35,"social_meta":78,"head_meta":80,"extra_data":82,"updated_unix":28},"simple-compound-interest-depreciation-growth-decay-h-maths-gcse-sample-questions","",{"@graph":36,"@context":77},[37,53,68],{"@type":38,"itemListElement":39},"BreadcrumbList",[40,44,48,51],{"item":41,"name":42,"@type":43,"position":20},"https://docshare.wps.com","Home","ListItem",{"item":45,"name":46,"@type":43,"position":47},"https://docshare.wps.com/document/","Document",2,{"item":49,"name":12,"@type":43,"position":50},"https://docshare.wps.com/document/exam/",3,{"item":52,"name":13,"@type":43,"position":11},"https://docshare.wps.com/document/simple-compound-interest-depreciation-growth-decay-h-maths-gcse-sample-questions/207758/",{"url":52,"name":13,"@type":54,"author":55,"headline":13,"publisher":57,"fileFormat":60,"inLanguage":23,"description":14,"dateModified":61,"datePublished":62,"encodingFormat":60,"isAccessibleForFree":63,"interactionStatistic":64},"DigitalDocument",{"name":9,"@type":56},"Person",{"url":41,"name":58,"@type":59},"DocShare","Organization","application/pdf","2026-09-08","2026-09-05",true,{"@type":65,"interactionType":66,"userInteractionCount":20},"InteractionCounter",{"@type":67},"ViewAction",{"@type":69,"mainEntity":70},"FAQPage",[71],{"name":72,"@type":73,"acceptedAnswer":74},"What is tested in the depreciation and interest questions?","Question",{"text":75,"@type":76},"They check correct compounding and how to interpret percentage changes across time.","Answer","https://schema.org",{"og:url":52,"og:type":79,"og:title":13,"og:site_name":58,"og:description":14},"article",{"robots":81,"canonical":52},"index,follow",{"doc_id":7,"site_id":24},{"code":4,"msg":5,"data":84},[85,89,93,96,101,106,111,115,119,122,126],{"id":20,"doc_module":4,"doc_module_name":46,"category_name":86,"show_sort_weight":87,"slug":88},"Story & Novel",90,"story-novel",{"id":47,"doc_module":4,"doc_module_name":46,"category_name":90,"show_sort_weight":91,"slug":92},"Literature",80,"literature",{"id":11,"doc_module":4,"doc_module_name":46,"category_name":12,"show_sort_weight":94,"slug":95},70,"exam",{"id":97,"doc_module":4,"doc_module_name":46,"category_name":98,"show_sort_weight":99,"slug":100},5,"Comic",60,"comic",{"id":102,"doc_module":4,"doc_module_name":46,"category_name":103,"show_sort_weight":104,"slug":105},6,"Technology",50,"technology",{"id":107,"doc_module":4,"doc_module_name":46,"category_name":108,"show_sort_weight":109,"slug":110},7,"Healthcare",40,"healthcare",{"id":21,"doc_module":4,"doc_module_name":46,"category_name":112,"show_sort_weight":113,"slug":114},"Research & Report",30,"research-report",{"id":116,"doc_module":4,"doc_module_name":46,"category_name":117,"show_sort_weight":29,"slug":118},9,"Religion & Spirituality","religion-spirituality",{"id":29,"doc_module":4,"doc_module_name":46,"category_name":120,"show_sort_weight":29,"slug":121},"World Cup","world-cup",{"id":123,"doc_module":4,"doc_module_name":46,"category_name":124,"show_sort_weight":123,"slug":125},10,"Lifestyle","lifestyle",{"id":127,"doc_module":4,"doc_module_name":46,"category_name":128,"show_sort_weight":97,"slug":129},19,"General","general"]