MATH GRE 5
Working alone, pump A can empty a pool in 3 hours. Working alone, pump B can empty the same pool in 2 hours. Working together, how many minutes will it take pump A and pump B to empty the pool?
1/5/6
Of all the nations with populations greater than 500,000 who are not members of NATO, approximately what percent of them use the euro as their primary currency?
6/17
From a total of 5 boys and 4 girls, how many 4-person committees can be selected if the committee must have exactly 2 boys and 2 girls?
order is not matter.
Dharik lives in a house on a straight street. For years, there have been 16 houses on his street to the right of his house and 17 houses on his street to the left of his house. Last year, 5 new houses were built on the same street even further to the left of those houses to the left of Dharik's house. If these are the only houses on this street, how many houses are on this street?
38+ Drarik house = 39
Perhaps the easiest way to calculate this on the GRE calculator first is type 1.06 and hit M+ to store this number in memory. Then, when it's still on the screen, hit \times× then equals: this gives 1.1236, which is 1.062. Then hit \times× then MR then equals: this gives 1.191016, which is 1.063. Then hit \times× then MR then equals: this gives 1.2624769, which is 1.064. Then hit \times× then MR then equals: this gives 1.3382255, which is 1.065. That's our denominator: while that's still on the screen, hit MC to clear the memory, and M+ to store this denominator in memory now. Now, you can hit C for clear, and type 1000 \div÷MR equals, and this gives us 747.25817, which rounds to $747.26. Resist the temptation to avoid using the memory keys and simply write down what you see on your screen: the problem with doing this is that the calculator always "knows" more digits than it shows on the screen, so if you do the next calculation only with what you see, you will not have available the off-screen digits, and the difference could affect how a decimal is rounded.
Melanie invests P dollars in a certificate of deposit that increases in value at 6% compounding annually each year for five years. At the end of five years, the certificate is worth $1000. What was the value of P? Give your answer to the nearest 0.01 dollars.
