Answer:
135 pennies
Step-by-step explanation:
x= pennies in the door at the start
x-1/3x-1/3(x-1/3x)-1/3(x-1/3x-1/3(x-1/3x))=40
x = 135
Proof: 135-45-20 =40
135-45=90
90=30=60
60-20=40
The number of pennies in the door at the start was 135 if Alice takes 1/3 of the pennies from the jar.
Fraction number consists of two parts, one is the top of the fraction number which is called the numerator and the second is the bottom of the fraction number which is called the denominator.
We have:
Alice takes 1/3 of the pennies from the jar. Then Brett takes 1/3 of the remaining pennies from the jar.
Finally, Carla takes 1/3 of the remaining pennies from the jar, leaving 40 pennies in the jar.
Let x be the pennies in the door at the start.
From the question we can frame a linear equation in one variable:
x - (1/3)x - (1/3)[x - 1/3x] - (1/3)[x - (1/3)x - (1/3){x - 1/3x}] = 40
x - (1/3)x - (1/3)x + 1/9x - (1/3)x + (1/9)x + (1/9){x - 1/3x}] = 40
x - (1/3)x - (1/3)x + 1/9x - (1/3)x + (1/9)x + (1/9)x - 1/27x = 40
3/x - x/27 = 40
8x = 1080
x = 135
Thus, the number of pennies in the door at the start was 135 if Alice takes 1/3 of the pennies from the jar.
Learn more about the fraction here:
brainly.com/question/1301963
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