Question 503044
Sales price:
Thermometer = $2
Hot-water bottle = $6
Total sales = $1200

Let x denote the quantity of hot-water bottles. Therefore, the quantity of thermometers will be 7x

Total sales = price * quantity

=> (7x*$2)+(x*$6)=$1200
    {{{14x+6x    =1200}}}
           {{{20x=1200}}}
             {{{x=1200/20}}}
X=60 

Therefore 60 items of Hot-water bottles and 420(7*60) items of thermometers were sold.

Verification:
Hot-water bottles: Qty= 60items      ; price= $6 per 
Thermometers:      Qty= 420items     ; price= $2 per item

Total sales = (60*$6)+(420*$2) = $1200