Download Pizitz Mathematics Tournament 2009

Pizitz Mathematics Tournament 2009
Seventh Grade Ciphering
Answers
1-1 Simplify: 4 – 36(6 · 6 – 6)+ 18 – 6(-1).
1-1
–1052
1-2 Botong can solve a problem in 3 hours, but Tony takes 6 hours to solve
the same problem. Working together, how many hours will it take them
to solve the problem?
1-2
2
1-3 Evaluate.
6 !5! 4!
5! 4 !3!
1-4 Write 0.153 as a simplified fraction.
1-3 120
1-4
23
/150
1-5 6, x = 6, or {6}
1-5 Solve for x: 6x – 10 – 8 + 2x – 7 = 3x + 5.
2-1 28%
2-1 Find the percent of decrease for a temperature drop from 75° to 54°.
2-2 110112 + 101012 = ________ 10
2-2 48
2-3 Find the ratio of the area of a right triangle to the hypotenuse if the leg
lengths are three and four.
2-3 6:5, 6/5 or 6 to 5
2-4 Find x if |x - 1| = |x - 2|.
2-5 How many feet are in 1 mile, 45 yards, 5 feet, and 60 inches?
2-4 1.5, 3/2 or 1 ½
2-5 5425
3-1 Find the LCM of 75, 25, and 33.
3-1 825
3-2 Find 14 2/7 % of 112.
3-2
16
3-3 Two angles are supplementary, and their measures are in the ratio 7:2.
Find the measure of the smaller angle.
3-3
40 or 40°
3
3-4 Evaluate.
64 4  2  19  2
4-1 Find A·B +C if A = number of primes less than 50, B = largest one digit prime
number, and C = mean of A and B.
4-2 If x ♥ y = 6x + y4, then evaluate (2♥5) ♥3.
4-3 Find the surface area of a right circular cylinder with a radius of 5 and
a height of 9. Leave pi in the answer.
4-4 Find the sum of 0.18 and 27.27% as a simplified fraction.
184
/5, 36 4/5
or 36.8
81  2 2
3-5 Find the sum of the exponents in the prime factorization of 420.
4-5
3-4
3-5
5
4-1 116
4-2
3903
4-3 140π
4-4
5
/11
4-5
26
Ex1
1
Evaluate: 27 – (-3)2 + |(-512)1/3| – [(24 – 42) · 63989].
Ex1 Jenny rolled a pair of 10-sided dice. Find the probability that the sum
of the two numbers is 11.
Ex2 Find the sum of the interior angle measures of a dodecagon.
Ex3 If 3600 students go to Smith School and the ratio of pros to newbies is 7:5,
find the difference between pros and newbies,
/10
Ex2 1800 or 1800°
Ex3 600