A fixer uses 30% of the nails in a container to repair the kitchen. He also used 70% of the remaining nails in the container to repair the fence. If there were 400 nails in the container, how many nails are remaining?
The fixer used 30/100*400 = 
<gadget id="calculator">30/100*400</gadget>
<output>120</output>
120 nails to fix the kitchen.
The number of nails remaining in the container after he fixes the kitchen is 400-120 = 
<gadget id="calculator">400-120</gadget>
<output>280</output>
280.
He also uses 70/100*280 = 
<gadget id="calculator">70/100*280</gadget>
<output>196</output>
196 of the nails remaining in the container to fix the fence.
The total number of nails which the fixer hasn't used is 280-196 = 
<gadget id="calculator">280-196</gadget>
<output>84</output>
84.

<result>84</result>