Bunuel
Solution X contains 4*10^(–2) grams of sugar. Solution Y contains 8*10^2 grams of sugar. The number of grams of sugar in solution Y is how many times the number of grams of sugar in solution X?
(A) 0.0002
(B) 0.002
(C) 200
(D) 2,000
(E) 20,000
Y, number of grams of sugar =
\(8*10^2\)X, number of grams of sugar =
\(4*10^{-2}\)Number of grams of sugar in Y is how many times the number of grams of sugar in X?
\(\frac{Y}{X}=\frac{8*10^2}{4*10^{-2}}=\)?1) Move
\(10^{-2}\) to the numerator.
Any number with a negative power in the denominator can be moved to the numerator.
Change the exponent's sign
\(\frac{Y}{X}=\frac{8*10^2}{4*10^{-2}}=\frac{8*10^2*10^2}{4}=\)
\(\frac{8*10^{(2+2)}}{4}=\frac{8*10^4}{4}=2*10^{4}=20,000\)OR
2) Division of exponents (same base) =
Keep the base, subtract the exponents
\(\frac{Y}{X}=\frac{8*10^2}{4*10^{-2}}=\frac{8*10^{2-(-2)}}{4}=\)
\(\frac{8*10^{2+2}}{4}=\frac{8*10^4}{4}=2*10^4=20,000\)OR
3) divide integers, then powers of 10.
Integers and powers of 10 are factors of the numbers. Results of separate operations are also factors -- i.e., multiply the results
Number in Y is how many times number in X?
Number in Y =
\(8*10^2\)Number in X =
\(4*10^{-2}\)\(\frac{8}{4} = 2\)
\(\frac{10^2}{10^{-2}}=10^{2-(-2)}=10^{2+2}=10^4\)
Multiply results: \(2*10^4=20,000\)Answer E