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1 vote
Dennis thought of a number. He adds 0.5 to that number and then multiplies the new result by 4. He then subtracts 2 and divides the number by 2. His final answer is 48. What number did Dennis start with?

User TDrudge
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2 Answers

2 votes

Let the number Dennis thought be x.

He adds 0.5 to that number and then multiplies the new result by 4.

The new number now is 4(x+0.5) He then subtracts 2 and divides the number by 2.The new number formed is
(4(x+0.5)-2)/(2)

Given His final answer is 48.

We can form an equation in x.


(4(x+0.5)-2)/(2) =48

To solve for x we multiply both sides by 2 to get

4(x+0.5)=96

4x+2=96

Subtracting 2 both sides

4x=94

Dividing both sides by 4:

x=24.

The number Dennis thought is 24.



User Zeyger
by
5.6k points
1 vote
Let the x be the number
So,
(4(x+0.5)-2)/2=48
So,
x=24 is the number.
User Tom Miller
by
5.8k points