A tablet battery charges at a constant rate of r percentage points per hour. If the batter… — ACT

A tablet battery charges at a constant rate of $r$ percentage points per hour. If the battery charge increases by $48$ percentage points in $3$ hours, which of the following equations can be used to find $r$ ?

A
$r + 3 = 48$
$3r = 48$ Cevap
C
$\frac{r}{3} = 48$
D
$r - 3 = 48$
E
$\frac{3}{r} = 48$

Cevap

The equation

3r = 48

can be used to find the charging rate.

The battery charges at a constant rate of

r

percentage points per hour. Over

3

hours, the total increase is the rate multiplied by the time, which is

3r

. Since the total increase is given as

48

percentage points, the correct relationship is expressed by the equation

3r = 48

Adım Adım Çözüm

Identify the relationship between the charging rate, time, and total charge increase.

The total charge increase is equal to the charging rate multiplied by the number of hours.

Since the battery charges at a constant rate of

r

percentage points per hour, in

3

hours it will charge a total of

3 \times r

3r

percentage points.

Set the expression for the total charge increase equal to the given total increase value.

3r = 48

The total charge increase is given as

48

percentage points, so we set the expression

3r

equal to

48

Anahtar Kavram

Translating a real-world scenario involving a constant rate into a one-step linear equation.

Alternatif Yöntem

You can also solve for the rate first by dividing the total increase of

48

3

hours to get

r = 16

percentage points per hour. Substituting

r = 16

into the equations shows that only

3(16) = 48

is a true statement.

Tahmini Süre:45s

Soru

Cevap

Adım Adım Çözüm

Anahtar Kavram

Sık Yapılan Hatalar

Alternatif Yöntem

Konular

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