Two alloys,A and B,are each made up of copper,zinc znd tin.In alloy A,the ratio of copper to zinc is 3:2 and the ratio of zinc to tin is 3:5.

Class: Form 1

Subject: Mathematics

Topic: Rates, Ratios, Proportions and Percentages

Lesson Summary

Two alloys,A and B,are each made up of copper,zinc znd tin.In alloy A,the ratio of copper to zinc is 3:2 and the ratio of zinc to tin is 3:5.
a)Determine the ratio, copper:zinc:tin in alloy A.
b)The mass of alloy A is 250kg.Alloy B has the same mass as alloy A but the amount of copper is 30% less than that of alloy A,Calculate.
i)The mass of tin in alloy A
ii)The total mass of zinc and tin in alloy B.
c)Given that ratio of zinc to tin in alloy B is 3:8,determine the amount of tin in alloy B than in alloy A.

---

More Video Lessons

---

• A farmer had 540 bags of maize each having a mass of 112kg.After drying the maize,the mass decreased in the ratio 15:16.
  

  A farmer had 540 bags of maize each having a mass of 112kg.After drying the maize,the mass decreased in the ratio 15:16.
  a)Calculate the total mass lost after the maize was dried.
  b)A trader bought and repacked the dried maize in 90kg bags.He transported the maize in a lorry which could carry a maximum of 120 bags per trip.
  i)Determine the number of the trips the lorry made.
  ii)The buying price of a 90kg bag of maize was ksh 1,500.The trader paid ksh 2,500 per trip to transport the maize to the market.He sold the maize and made a profit of 26%.Calculate the selling price of each bag of the maize.
  

  Date posted: April 10, 2019

• Three partners Amina,Bosire and Karuri contributed a total of ksh 4800000 in the ratio 4:5:7 to buy an 8 hectares piece of land.
  

  Three partners Amina,Bosire and Karuri contributed a total of ksh 4800000 in the ratio 4:5:7 to buy an 8 hectares piece of land.The partners set aside 14 of the land for social amenities and sub-divided the rest into 15m by 25m plots.
  a)Find
  i)the amount contributed by Karuri.
  ii)the number of plots that were obtained.
  
  b)The partners sold the plots at Ksh 50,000 each and spent 30% of the profit realized to pay for administrative costs.They shared the rest of the profit in the ratio of their contributions .
  i)Calculate the net profit realized.
  ii)Find the difference in the amount of profit earned by Amina and Bosire.
  
  
  

  Date posted: April 10, 2019

• Three business partners Abila,Bwire and Chirchir contributed Ksh 120,000, Ksh 180,000 and Ksh 240,000 respectively, to boast their business.
  

  Three business partners Abila, Bwire and Chirchir contributed ksh 120,000,ksh 180,000 and ksh 240,000 respectively,to boast their business.They agreed to put 20% of the profit accrued back into the business and to use 35% of the profit for running the business(official operations).The remainder was to be shared among the business partners in the ratio of their contribution.At the end of the year,a gross profit of ksh.225,000 was realized.
  
  a)Calculate the amount:
  i)Put back into the business.
  ii)Used for official operations.
  b)Calculate the amount of profit each partner got.
  c)If the amount put back into the business was added to individuals’s shares proportionately to their initial contribution,find the amount of chirchir’s new shares.

  Date posted: April 10, 2019

View all video lessons