2 iPhones cost $1,680, how much would 10 iPhones cost?

$8,400

Step-by-step explanation:

one way to solve it would be that since you know 2 x 5 = 10 you can do $1,680 x 5 and that = $8,400

triangle and cube

step-by-step explanation:

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.