Question

A new toy hits the local store. Sales (in hundreds) increase at a steady rate for several months, then decrease at about the same rate. This can be modeled by the function S(m)=-0.625\left|\mathrm{m}-8\right|+5S(m)=−0.625∣m−8∣+5 In what month(s) were 400 toys sold? A) 7th and 10th B) 5th C) 5th and 11th D) 4th and 12th

Answer 1

Answer:

Option A.

Step-by-step explanation:

It is given that, sales (in hundreds) for several months can be modeled by the function:

$S(m)=-0.625|m-8|+5$

We need to find the month in which 400 toys were sold.

Substitute S(m)=4 in the given function.

$4=-0.625|m-8|+5$

$4-5=-0.625|m-8|$

$-1=-0.625|m-8|$

$\dfrac{-1}{-0.625}=|m-8|$

$1.6=|m-8|$

Now,

$\pm 1.6=m-8$

$1.6=m-8$ or $-1.6=m-8$

$1.6+8=m$ or $-1.6+8=m$

$9.6=m$ or $6.4=m$

Approx the value to the next whole number.

$m\approx 10$ or $m\approx 7$

It means, 400 toys were sold on 7th and 10th month.

Therefore, the correct option is A.