the cost of operating an appliance varies jointly as the number of watts drawn, the hours of the operation and the cost per kilowatt-hour. At P8.99 per kilowatt-hour, how much would it cost when a 70-watt desk fan operates for 2 hours?

Answer 1

c = kwhp
You do not give any way to evaluate k
c = 70*2*8.99 = 1258.6k
Now supply the constant of variation, k.

Answer 2

Thank u to your helpful answer

Answer 3

What is the answer of that

Answer 4

Solution:
suppose: cost of appliance (c), number of watts (w), hours (h) and cost per kilowatt hour (p)
Math sentence:
c = kwhp
substitute:
c = k (70)(2)(8.99)
c = (1)(1258.6)
c = 1256.6
Therefore the cost of operation is 1,256 pesos and 6 centavos