<p><a href="http://i.imgur.com/kgYxqUZ.png%5B/url%5D">http://i.imgur.com/kgYxqUZ.png</a></p>
<p>Answers are 1000 and 8521</p>
<p>20<em>5</em>10=1000 cm
1m equals 100cm
100<em>100</em>100= 1,000,000 cm
1,000,000 cm divided by 1000cm equals 1000</p>
<p>Indianboy has #17. Except for the units. The units should be:</p>
<p>
Here’s #18.</p>
<p>The key piece of information here is the third requirement, that the product of the four digits be a multiple of 10, but not 0. That tells you a couple of things. First, there is no 0 in the number; if there were, the product of its four digits would be 0. Second, there must be a 2 and a 5. Using only single-digit numbers, the only way to make 10 by multiplication is 2*5; the only way to have the product of all four digits by a multiple of 10 is for that product to have a 2 and a 5 in its prime factorization.</p>
<p>Now, we know two of the digits are 2 and 5. We also know that one digit is the sum of the other three. Let’s work on finding not the sum, but the other addend. Let’s make it as big as possible. 2 + 5 = 7 already. The sum of all 3 digits can’t exceed 9, because the sum of the three digits has to equal the fourth digit. Another 2 would make the sum of those digits be 9, but that would violate the requirement that all the digits be different. So the third digit can’t be 2, and it can’t be greater than 2, and it can’t be 0. It must be 1.</p>
<p>The fourth digit is the sum of the other three: 5 + 2 + 1 = 8. </p>
<p>Now, to get the greatest number possible, put the largest digit in the thousands place, the next largest in the hundreds place, the next largest in the tens place, and the remaining digit in the ones place. Voila: 8,521.</p>
<p>For the first one, you first convert the measurements to meters.
.2 meters, .05 meters, and .1 meters. You then multiply those three to find the volume which is .001m^3 now you just divide 1/.001=1000</p>
<p>I had trouble with the second one but it was already answered on another forum. For your convenience, i shall paste it here</p>
<p>Since the product is divisible by 10 and not equal to zero, we know two of the number must be the factors of 10, 2 and 5. 2<em>5</em>x<em>y=10</em>z=divisible by ten.
The greatest digit is the sum of the other three. We start with the largest digit, 9, since we want the greatest number. But 9 doesn’t work, since if we have 2+5+x=9, x=2, which violates the “all of the integers are different rule.” But if we use 8, x=1.
We then know the digits are 1, 2, 5, and 8. We arrange these in decreasing order to get the greatest number: 8521.</p>
<p>written by quomodo</p>
<p>Thank you for the rplies</p>