<p>1)What is the greatest four-digit integer that meets the following three restrictions?
1. All of the integers are different
2.The greatest digit is the sum of the other three digits
3.the product of the four digits is divisible by 10 and not equal to zero</p>
<p>the answer 8521</p>
<p>I got the answer of this question but it took me alot of time that I'd rather not waste in the exam so I wanted if there is a faster method</p>
<p>2)A rectangular solid has length 20 centimeters, width 5 centimeters, and height 10 centimeters. How many of these rectangular solids when combined have a volume of 1 cubic meter? ( 1 meter= 100 centimeter)</p>
<p>3)A bakery sells 4 different types of bread. How many combinations of 3 different types of bread can a customer buy from this bakery?</p>
<p>4)If b>1, what is the slope of the line in the xy- plane that passes through the points (b,b^2) and (b^2,b^4)</p>
<p>1) Remember that you do not have to solve the problem- you just have to pick the correct answer. Look at the multiple choice answers. Go through each criteria. Of the ones that fit, pick the highest. That should save you a lot of time.</p>
<p>2) First convert to meters. 20cm=.2m, 5cm=.05m, 10cm=.1m. Then multiply. With decimals, remember to multiply the numbers without them, then count how many you need. For example, 2<em>5</em>1=10 and you need 4 decimal spots. Thus, each block is .0010 cubic meters. 1000 blocks can fit in 1 cubic meter.</p>
<p>3) The bakery has 4 choices for the first bread, 3 for the second, and 2 for the third. This makes 24 combinations. (4<em>3</em>2)</p>
<p>4) Slope intersect form is good here. m=slope.
(b^4-b^2)=m(b^2-b) … Then simplify
b^2(b^2-1)=bm(b-1)
b(b-1)(b+1)=m(b-1)
b(b+1)=m
(b^2+b)=m</p>
<p>Thank you, Omniwrench5 but ur wrong in number 3, I did it the same way, the answer is 4 and is it possible to solve number 4 with the y2-y1/x2-x1 rule?</p>
<p>Agree with all of those… i can’t seem to think of a easy way for 1 though which i would say is probably a grid in question.</p>
<p>The bakery one is 4. You could use 4C3, because order does not matter – buying white, rye and wheat is the same as buying rye, wheat and white.</p>
<p>But there is an easier way: If they sell 4 types and you are buying three types, that is the same thing as picking one of the 4 types to NOT buy. Since there are obviously 4 ways to do that, there must be 4 ways to pick 3.</p>
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<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>