Mathematics questions and answers

Mathematics Questions and Answers

How good are you with figures and formulas? Find out with these Mathematics past questions and answers. This Test is useful for both job aptitude test candidates and students preparing for JAMB, WAEC, NECO or Post UTME.

4,006.

If \(\frac{({a^2b^{-3}c})^{3/4}}{a^{-1}b^4c^5}\) = \(a^p b^q c^r\); what is the value of p+2q?

A.

(5/2)

B.

-(5/4)

C.

-(25/4)

D.

-10

Correct answer is D

Hint: Use BODMAS and algebra to arrive at the values of P = 5/2, q = -25/4 and r = -9/2.
Then substitute the values of p and q into p+2q to get -10.

4,007.

If \(\frac{(a^2 b^{-3}c)^{\frac{3}{4}}}{a^{-1}b^{4}c^{5}}=a^{p} b^{q} c^{r}\) What is the value of p+2q?

A.

(5/2)

B.

-(5/4)

C.

-(25/4)

D.

-10

Correct answer is D

Hint: apply basic mathematics rules beginning from BODMAS to algebra, and follow solution carefully to arrive at

p = \(\frac{5}{2}\), q = -\(\frac{25}{4}\) and r = -\(\frac{17}{4}\)

 

NUMERATOR:   a\(^{\frac{2}{1}}*{\frac{3}{4}}\)          b\(^{\frac{-3}{1}}*{\frac{3}{4}}\)          c\(^{\frac{1}{1}}*{\frac{3}{4}}\)

                           a\(\frac{3}{2}\)      b\(\frac{-9}{4}\)    c\(\frac{3}{4}\)

Using index method for numerator & denominator :  a\(^{\frac{3}{2}}-{\frac{-1}{1}}\)           b\(^{\frac{-9}{4}}-{\frac{4}{1}}\)           c\(^{\frac{3}{4}}-{\frac{5}{1}}\)

:  a\(\frac{5}{2}\)      b\(\frac{-25}{4}\)    c\(\frac{-17}{4}\)

Then p+2q will give you \(\frac{5}{2}+2\left(\frac{-25}{4}\right)= -10\)

4,008.

Find the value of X if \(\frac{\sqrt{2}}{x+\sqrt{2}}=\frac{1}{x-\sqrt{2}}\)

A.

3√2+4

B.

3√2-4

C.

3-2√2

D.

4+2√2

Correct answer is A

Start your solution by cross-multiplying,

\(\frac{\sqrt{2}}{x+\sqrt{2}}=\frac{1}{x-\sqrt{2}}\)

[x - √2] √2  = x + √2

where √2×√2=2 

x√2 - √2 * √2 = x + √2

then collect like terms

x√2 - x = √2 + 2

and factorize accordingly to get the unknown.

x(√2 - 1) = √2 + 2

x = \(\frac{√2 + 2}{√2 - 1}\)

rationalize 

x = \(\frac{√2 + 2}{√2 - 1}\) * \(\frac{√2 + 1}{√2 + 1}\)

x = \(\frac{√4 + √2 + 2√2 + 2}{√4  + √2 - √2 - 1}\)

x = \(\frac{2 +  3√2 + 2}{2 - 1}\)

x =  \(\frac{3√2 + 4}{1}\)

x = 3√2 + 4

4,009.

If log 10 to base 8 = X, evaluate log 5 to base 8 in terms of X.

A.

\(\frac{1}{2}\)X

B.

X-\(\frac{1}{4}\)

C.

X-\(\frac{1}{3}\)

D.

X-\(\frac{1}{2}\)

Correct answer is C

\(log_810\) = X = \(log_8{2 x 5}\)

\(log_82\) + \(log_85\) = X

Base 8 can be written as \(2^3\)

\(log_82 = y\)

therefore \(2 = 8^y\)

\(y = \frac{1}{3}\)

\(\frac{1}{3} = log_82\)

taking \(\frac{1}{3}\) to the other side of the original equation

\(log_85 = X-\frac{1}{3}\)

4,010.

A group of market women sell at least one of yam, plantain and maize. 12 of them sell maize, 10 sell yam and 14 sell plantain. 5 sell plantain and maize, 4 sell yam and maize, 2 sell yam and plantain only while 3 sell all three items. How many women are in the group

A.

25

B.

19

C.

18

D.

17

Correct answer is A

Let the three items be M, Y and P.
n{M ∩ Y} only = 4-3 = 1
n{M ∩ P) only = 5-3 = 2
n{ Y ∩ P} only = 2
n{M} only = 12-(1+3+2) = 6
n{Y} only = 10-(1+2+3) = 4
n{P} only = 14-(2+3+2) = 7
n{M∩P∩Y} = 3
Number of women in the group = 6+4+7+(1+2+2+3) as above =25 women.