Students in class 3B are collecting school points for behavior. If they get enough points in total, they can go on a trip. In the class, there are Adam, Martha, Betty, and Tom. Adam has collected 50 points. Betty was better than Adam and collected 30% more. Marta managed to collect 3 times more points than Tom, who has 30 points less than Betty. How many points is the class missing to go on the trip if the minimum threshold is 400 points?
Betty has 30% more points than Adam, so it's 30/100 * 50 = 
<gadget id="calculator">30/100*50</gadget>
<output>15</output>
15 points more.
Betty's total is therefore 50 + 15 = 
<gadget id="calculator">50+15</gadget>
<output>65</output>
65 points.
Tom has 30 points less than Betty, so he has 65 - 30 = 
<gadget id="calculator">65-30</gadget>
<output>35</output>
35 points.
Marta has 3 times more points than Tom, so she has 3 * 35 = 
<gadget id="calculator">3*35</gadget>
<output>105</output>
105 points.
In total, all students collected 50 + 65 + 35 + 105 = 
<gadget id="calculator">50+65+35+105</gadget>
<output>255</output>
255 points.
So the class is missing 400 - 255 = 
<gadget id="calculator">400-255</gadget>
<output>145</output>
145 points to go on the trip.

<result>145</result>