Jane is saving her money in order to purchase a new racing bike. She initially saves $3 and plans to double the amount she saves each month. The bike Jane wants is $1,536 at the local bike shop.

Which equation represents this situation, and after how many months, t, will Jane have enough money to purchase the bike?

A, 3(2)t = 1,536; t = 11
B, 3(1.2)t = 1,536; t = 35
C, (3 · 2)t = 1,536; t = 9
D, 3(2)t = 1,536; t = 9

Respuesta :

the Answer is D)
i just did the math. plug 3(2)^9 in to a calculator!

Answer:

Hence, option: D is true.

D) 3×(2)^t = 1,536; t = 9

Step-by-step explanation:

Jane is saving her money in order to purchase a new racing bike. She initially saves $3 and plans to double the amount she saves each month.

he bike Jane wants is $1,536 at the local bike shop.

The equation that represents this situation, and after how many months, t, will Jane have enough money to purchase the bike is:

D) 3×(2)^t = 1,536; t = 9

since in the first month the cost is:

[tex]C_1=3\times 2[/tex]

in next month the cost is:

[tex]C_2=3\times 2\times 2\\\\C_2=3\times 2^2[/tex]

in t=3 months the expression is:

[tex]C_3=3\times 2^2\times 2\\\\C_3=3\times 2^3[/tex]

Hence in general we say:

[tex]C_t=3\times 2^t[/tex]

Hence,

[tex]3\times 2^t=1536\\\\2^t=\dfrac{1536}{3}\\\\2^t=512\\\\2^t=2^9\\\\t=9[/tex]

Hence, option: D is true.

D) 3×(2)^t = 1,536; t = 9