Ethan is reading a sci-fi book that has 360 pages. He read 40 pages on Saturday morning and another 10 pages at night. The next day he read twice the total pages as on Saturday. How many pages does he have left to read?
Ethan read a total of 40 pages + 10 pages = 
<gadget id="calculator">40+10</gadget>
<output>50</output>
50 pages on Saturday.
On the next day, he read a total of 50 pages x 2 = 
<gadget id="calculator">50*2</gadget>
<output>100</output>
100 pages.
The total number of pages that Ethan had read is 50 pages + 100 pages = 
<gadget id="calculator">50+100</gadget>
<output>150</output>
150 pages.
Therefore, Ethan has 360 pages - 150 pages = 
<gadget id="calculator">360-150</gadget>
<output>210</output>
210 pages left to read.

<result>210</result>