If 7 + y = 4 (mod 8), find the least value of y, 10 \(\leq y \leq 30\)
11
13
19
21
Correct answer is B
7 + y = 4 (mod 8)
y = 4 - 7 (mod 8)
y = -3 + 8 (mod 8)
y = 5 + 8 (mod 8)
y = 13
Simplify, correct to three significant figures, (27.63)\(^2\) - (12.37)\(^2\)
614
612
611
610
Correct answer is D
(27.63)\(^2\) - (12.37)\(^2\)
= (27.63 + 12.37)(27.63 - 12.37)
= 40 x 15.26
= 610
Solve: \(\frac{y + 1}{2} - \frac{2y - 1}{3}\) = 4
y = 19
y = -19
y = -29
y = 29
Correct answer is B
\(\frac{y + 1}{2} - \frac{2y - 1}{3}\) = \(\frac{4}{1}\)
- \(\frac{3(y + 1) - 2(2y - 1)}{6} = \frac{4}{1}\)
3y + 3 - 4y + 2 = 24
- y + 5 = 24
- y = 24 - 5 = 19
y = - 19
Evaluate: (0.064) - \(\frac{1}{3}\)
\(\frac{5}{2}\)
\(\frac{2}{5}\)
-\(\frac{2}{5}\)
-\(\frac{5}{2}\)
Correct answer is A
(0.064)\(^{- \frac{1}{3}}\)
= (\(\frac{64}{1000}\))\(^{-\frac{1}{3}}\)
= 3\(\sqrt{\frac{1000}{64}}\)
= \(\frac{10}{4}\)
= \(\frac{5}{2}\)
Express, correct to three significant figures, 0.003597.
0.359
0.004
0.00360
0.00359
Correct answer is C
0,00 3597 = 0.00360 to 3 s.f