You buy a computer for $1200. The value of the computer decreases by 30% each year. Find the value of the computer after 4 years.

The amount of 30% is $ 1200 * 30 / 100 = $360,

y1 = $360 (year 1), so let's find y2

the amount of 30% is $360*30/100 = $108

let 's find y3,

the amount of 30% is $108*30/100 = $32.4

let 's find y4

the amount of 30% is $32.4*30/100 = $9.72

so the value of the computer after 4 years is $9.72