Question Detail
a * b = 2a - 3b + ab, then 3*5 + 5*3 = ?
- 20
- 21
- 22
- 23
Answer: Option C
Explanation:
= 2(3)-3(5)+(3*5) + 2(5)-3(3)+(5*3)
= 6-15+15+10-9+15 = 31-9 = 22
1. Simplify
\begin{aligned}
\frac{\frac{7}{2}\div {\frac{5}{2}} \times {\frac{3}{2}} }{\frac{7}{2} \div { \frac{5}{2}} of \frac{3}{2} } \div 5.25
\end{aligned}
- \begin{aligned} \frac{3}{5} \end{aligned}
- \begin{aligned} \frac{3}{6} \end{aligned}
- \begin{aligned} \frac{3}{7} \end{aligned}
- \begin{aligned} \frac{3}{8} \end{aligned}
Answer: Option C
Explanation:
\begin{aligned}
\frac{\frac{7}{2}\div {\frac{5}{2}} \times {\frac{3}{2}} }{\frac{7}{2} \div { \frac{5}{2}} of \frac{3}{2} }\div 5.25
\end{aligned}
\begin{aligned}
= \frac{\frac{7}{2}\times {\frac{2}{5}} \times {\frac{3}{2}} }{\frac{7}{2} \div { \frac{15}{4}}}\div 5.25
\end{aligned}
\begin{aligned}
= \frac{\frac{21}{10}}
{\frac{7}{2} \times { \frac{4}{15}}}\div {\frac{525}{100}}
\end{aligned}
\begin{aligned}
= \frac{21}{10}\times{\frac{15}{14}}\times\frac{100}{525}
= \frac{6}{14}
= \frac{3}{7}
\end{aligned}
2. \begin{aligned}
\frac{4+4 \times 18 -6 - 8}{123 \times 6 - 146 \times 5 }
\end{aligned}
- 7.50
- 7.75
- 8
- 8.05
Answer: Option B
Explanation:
\begin{aligned}
\frac{4+72-6-8}{738-730}
\end{aligned}
\begin{aligned}
= \frac{76-14}{8}
\end{aligned}
\begin{aligned}
= \frac{62}{8} = 7.75
\end{aligned}
3. Company workers decided to raise Rs. 3 lakhs by equal contribution from each. Had they contributed Rs. 50 each extra, the contribution would have been Rs. 3.25 lakhs. How many workers were they?
- 300
- 400
- 500
- 600
Answer: Option C
Explanation:
N * 50 = (325000 - 300000) = 25000
N = 25000 / 50
= 500
4. 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}
5. In a class free notebooks were distributed among all the children. Each child got notebooks which were one-eighth of the number of children. If number of children been half, then each child would have recieved 16 notebooks in total. Find the total number of books distributed.
- 450
- 512
- 598
- 658
Answer: Option B
Explanation:
Let suppose total number of students in class are X.
Then from the question we can conclude it that,
\begin{aligned}
X*\frac{1}{8}X = \frac{X}{2}*16 \\
=> X = 64\\
\text{Total notebooks,} \\
= \frac{1}{8}X^2 \\
= \left( \frac{1}{8} * 64 * 64 \right) \\
= 512
\end{aligned}