At noon mr. white started driving from boston to philadelphia at average speed 60 mph. at what time will he arrive if he needs to cover 312 miles?

Mr White will arrive at 5:12 pm or 17:12 hrs

Step-by-step explanation:

Let

y ----> the distance in miles

x ----> the time i hours

we know that

A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form or

In this problem we have a proportional relationship between the variables x and y

The constant of proportionality k is equal to the speed

so

The linear equation is

At what time will he arrive if he needs to cover 312 miles?

For y=312 miles

substitute in the equation and solve for x

Mr White will arrive at 5:12 pm or 17:12 hrs

answer: first option i.e. 'a' is correct.

step-by-step explanation:

since we have given that

number of minutes to wrap a small gift box = 4 minutes

we need to find the number of gifts to be wrapped in 5 minutes

since there is a direct variation, as the number of minutes will increase with   number of gifts to be wrapped.

so, let the number of gifts to be wrapped in 5 minutes be x.

so, it becomes,

hence, first option 'a'   is correct.