Question 213145
There are 500 pupils in a school. in the next year, the numbers increase by 10% and in the following year they increase by 20%. find the number of pupils  at the end of two years.


Step 1.  Increase by 10% means 0.10*500=50 where 10 percent is 0.10 or 10%=0.10.


Step 2.  So at end of the first year there are 500+50=550 students.  Note:  Since you know there will be an increase you can use the following


{{{500(1+0.1)=550}}}


Step 3.  In year 2, it increase by 20%.  So, there is an increase of 550*0.20=  110 students.  Note:  Since you know there will be an increase you can use the following


{{{550(1+0.2)=660}}}


Step 4.  So at the end of the second year there are 550+110= 660 students.  Note:  You can also calculate by combining steps 2 and 3.


{{{500(1+0.1)(1+0.2)=660}}}


where 


{{{500(1+0.1)(1+0.2)=550(1+.2)=660}}}



I hope the above steps were helpful.


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Good luck in your studies!


Respectfully,
Dr J