Question

the cost of a phone call is c pence which is calculated using the formula c=20+5m where m is the number of minutes the phone call lasted find the value of c when 1)m=1 2)m=5 3)m=12

Answer 1

I believe the answer is 25 because it says that 2)m=5 or it may be 30 because 5times 2 equals 10 and 10plus 20 gives you 30