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The number of girls in a class are 7 times the number of boys, which value can never be the of total students

  • 40
  • 48
  • 24
  • 30

Answer: Option D

Explanation:

Let the boys are X, then girls are 7X, total = X+7X = 8X

So it should be multiple of 8, 30 is not a multiple of 8.

Similar Questions :

1. Simplfy
b - [b -(a+b) - {b - (b - a+b)} + 2a]

  • a
  • 2a
  • 4a
  • 0

Answer: Option D

Explanation:

b-[b-(a+b)-{b-(b-a+b)}+2a]
=b-[b-a-b-{b-(2b-a)}+2a]
=b-[-a-{b-2b+a}+2a]
=b-[-a-{-b+a}+2a]
=b-[-a+b-a+2a]
=b-[-2a+b+2a]
=b-b
=0

2. Find the value of X
X = (6/119) * (63/8) * (17/9)

  • 1/4
  • 2/4
  • 3/4
  • 4

Answer: Option C

3. What fraction of \begin{aligned} \frac{4}{7}\end{aligned} should be added to itself to become \begin{aligned} 1\frac{1}{14} \end{aligned}

  • \begin{aligned} \frac{7}{8} \end{aligned}
  • \begin{aligned} \frac{7}{9} \end{aligned}
  • \begin{aligned} \frac{7}{10} \end{aligned}
  • \begin{aligned} \frac{7}{11} \end{aligned}

Answer: Option A

Explanation:

\begin{aligned}
=> \frac{4}{7}x + \frac{4}{7} = \frac{15}{4}
\end{aligned}
\begin{aligned}
= \frac{4}{7}x = \frac{15}{4} - \frac{4}{7}
\end{aligned}
\begin{aligned}
= \frac{4}{7}x = \frac{7}{14}
\end{aligned}
\begin{aligned}
= x = \frac{1}{2}\times \frac{7}{4} = \frac{7}{8}
\end{aligned}

4. If a - b = 3 and \begin{aligned} a^2 + b^2 = 29 \end{aligned}, then find the value of ab

  • 7
  • 8.5
  • 10
  • 12

Answer: Option C

Explanation:

Remember the formula, if not then cram it :)
\begin{aligned} 2ab = (a^2 + b^2)- (a-b)^2 \end{aligned}
=> 2ab = 29 - 9 = 20
=> ab = 10

5. How many pieces of 0.85 meteres can be cut from a rod 42.5 meteres long

  • 30
  • 40
  • 50
  • 60

Answer: Option C

Explanation:

We need so simple divide 42.5/0.85,
=(4250/85) = 50

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