Leo had 400 marbles in a jar. He packed the marbles with ten marbles in each pack, and he gave some of them to his two friends,  Manny and Neil.   He gave Manny 1/4 of the number of packs of marbles, Neil received 1/8 of the number of packs of marbles, and he kept the rest. How many packs of marbles did Leo keep?
Leo had 400/10 = 
<gadget id="calculator">400/10</gadget>
<output>40</output>
40 packs of marbles.
He gave Manny 1/4 x 40 = 
<gadget id="calculator">1/4*40</gadget>
<output>10</output>
10 packs of marbles.
And, Neil received 1/8 x 40 = 
<gadget id="calculator">1/8*40</gadget>
<output>5</output>
5 packs of marbles.
Thus, Leo. gave a total of 10 + 5 = 
<gadget id="calculator">10+5</gadget>
<output>15</output>
15 packs of marbles.
Therefore, Leo kept 40 - 15 = 
<gadget id="calculator">40-15</gadget>
<output>25</output>
25 packs of marbles.

<result>25</result>