MathDB

Place all numbers from 1 to 10 to the boxes such that every number except the uppermost is equal to the difference between the two numbers on its top. [asy] unitsize(-4); draw((0,0)--(5,0)--(5,5)--(0,5)--cycle); draw((10,0)--(15,0)--(15,5)--(10,5)--cycle); draw((20,0)--(25,0)--(25,5)--(20,5)--cycle); draw((30,0)--(35,0)--(35,5)--(30,5)--cycle);
draw((5,10)--(10,10)--(10,15)--(5,15)--cycle); draw((15,10)--(20,10)--(20,15)--(15,15)--cycle); draw((25,10)--(30,10)--(30,15)--(25,15)--cycle);
draw((10,20)--(15,20)--(15,25)--(10,25)--cycle); draw((20,20)--(25,20)--(25,25)--(20,25)--cycle);
draw((15,30)--(20,30)--(20,35)--(15,35)--cycle);
draw((2.5,5)--(7.5, 10)); draw((12.5,5)--(17.5, 10)); draw((22.5,5)--(27.5, 10));
draw((32.5,5)--(27.5, 10)); draw((22.5,5)--(17.5, 10)); draw((12.5,5)--(7.5, 10));
draw((7.5,15)--(12.5, 20)); draw((17.5,15)--(22.5, 20));
draw((27.5,15)--(22.5, 20)); draw((17.5,15)--(12.5, 20));
draw((12.5,25)--(17.5, 30)); draw((22.5,25)--(17.5, 30)); [/asy]The number in the lower box is at most

<span class='latex-bold'>(A)</span>\ 1 \qquad<span class='latex-bold'>(B)</span>\ 2 \qquad<span class='latex-bold'>(C)</span>\ 3 \qquad<span class='latex-bold'>(D)</span>\ 4 \qquad<span class='latex-bold'>(E)</span>\ 5

11

Problems(1)