on a mobile phone, the battery charge level is usually displayed as a percentage between 0 and 100%. Erik's mobile is charged 19 percentage points per hour and Alva's mobile is charged at 51 percentage points per hour. both Erik's mobile and Alva's mobile are discharged by 7 percentage points per hour when they are not being charged. When Erik's mobile shows 49% and Alva's 15%, Erik starts charging his mobile. Alva starts charging 45 minutes later. Determine how long after Erik starts charging his mobile that both mobiles show the same percentage.
54
likes