If d1, d2, d3, d4 are four different integers, whether is 0.d1d2+0.d3d4 greater than 1?
1) The least number is 4
2) (0.d1d2)(0.d3d4)>0.5
1) The least number is 4
2) (0.d1d2)(0.d3d4)>0.5
Statement 1 is sufficient. Statement 1 tells us that our lowest possible values for d1 and d3 are respectively 4 and 5, and then for d2 and d4 they will be respectively 6 and 7, so we will be adding AT LEAST 0.46 + 0.57 and this is greater than 1.sud21 wrote:If d1, d2, d3, d4 are four different integers, whether is 0.d1d2+0.d3d4 greater than 1?
1) The least number is 4
2) (0.d1d2)(0.d3d4)>0.5
Statement 2 is not sufficient. We know if these are digits (and a real GMAT would have specified that they are, so we will know that they are equal to 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9) and different, neither of the two constructed numbers here will equal zero. So we can multiply and get:
0.d1d2 > (0.d3d4)0.5
But the two numbers could be, for example, 0.23 and 0.46 (answer is no), 0.32 and 0.64 (answer is no) or 0.43 and 0.86 (answer is yes).
