a phone company charges 10 cents per minute for the first 3 minutes of a call, and 10-c cents for each minute thereafter. what is the cost in cents of a 10 minute phone call?
a) 200-20c
b)100c+70
c)30+7c
d)100-7c
e)100-70c

Question

a phone company charges 10 cents per minute for the first 3 minutes of a call, and 10-c cents for each minute thereafter. what is the cost in cents of a 10 minute phone call?
a) 200-20c
b)100c+70
c)30+7c
d)100-7c
e)100-70c

terenzreignz · Answer

A ten minute call will certainly have the charge for the first three minutes, as it clearly exceeds that, so the subtotal would be

10(3)

That leaves seven more minutes after the first 3, meaning the charge for such minutes apply from here on forth. We add that to our subtotal....


10(3) + (10 - c)(7)

Work it out from here :)