Question

A phone company offers two monthly charge plans. In Plan A, the customer pays a monthly fee of

$6.20 and then an additional 7 cents per minute of use. In Plan B, there is no monthly fee, but the customer pays

9 cents per minute of use.

For what amounts of monthly phone use will Plan A cost more than Plan B?
Use m for the number of minutes of phone use in a month, and solve your inequality for m

.

Answer 1

• Plan A is = $6.20 + 7 cents per mins.
• Plan B is = $0 + 9 cents per mins.
• we have to find the number of minutes for which the Plan A costs more than the Plan B.
• the inequality is very simple :
• let minuets be 'm', and the $6.20 = 620 cents.
• 620 + 7*m > 0 + 9*m, this is the required inequality to find number of minutes m.
• 620 + 7*m - 7*m > 9*m -7*m    (Adding -7*m to both sides).
• 620 > 2*m, we get
• m < 620/2,
• m < 310.
• ANSWER---------> for plan A to be more costly than plan B the number of minutes mut be less than 310 in whole month, i.e. m < 310.