Answer is (d)

Let her monthly salary be ₹ x.

According to the question

\(\displaystyle \frac{7}{{100}}\times x=2170\)

\(\displaystyle \Rightarrow \)x= \(\displaystyle x=\frac{{2170\times 100}}{7}=31000\)

Total monthly investment = (18 + 6 + 7)% of 31000

\(\displaystyle \frac{{31}}{{100}}\times 31000=9610\)

Total annual investment = 12 × 9610 = ₹ 115320

Answer is (e)

Let the original fraction be \(\displaystyle \frac{x}{y}\)

According to the question,

\(\displaystyle \frac{{x\times 400}}{{y\times 600}}=\frac{5}{{12}}\)

\(\displaystyle \Rightarrow \)\(\displaystyle \frac{x}{y}=\frac{5}{{12}}\times \frac{6}{4}=\frac{5}{8}\)

Answer is (c)

Let Ms. Pooja monthly salary = ₹ x

According to the question,

13% of the x = ₹8554

\(\displaystyle \Rightarrow \)\(\displaystyle x=\frac{{8554\times 100}}{{13}}\)

= Rs. 65800

Total monthly investment in percentage= 13 + 23 + 8 = 44

Therefore, Total monthly investment = 44% of ₹65800

=\(\displaystyle \frac{{44\times 65800}}{{100}}\)

= ₹ 28952

Therefore, total annual investments= (12 × 28952)

= 347424

Answer is (c)

Number of sweets received by each student= 15% of 240

=\(\displaystyle \frac{{15\times 240}}{{100}}=36\)

Therefore, total number of sweets = 240 × 36 = 8640

Answer is (c)

Sen’s monthly income = \(\displaystyle \frac{{775200}}{{12}}=64600\)

Let the monthly income of Anita be Rs. x.

Therefore, Bina’s monthly income = \(\displaystyle \frac{{90\times x}}{{100}}=0.9x\)

Now, according to the question,

x+0.9x=64600

\(\displaystyle \Rightarrow \)\(\displaystyle \frac{{64600}}{{1.9}}=34000\)

Bina’s monthly income = 34000 × 0.9 = ₹ 30600

Answer is (c)

Let the money of C be x.

According to the question,

Total money of B = x + x + 50%

=\(\displaystyle x+\frac{{50x}}{{100}}=\frac{{3x}}{2}\)

Total money of A = \(\displaystyle 2\times \frac{{3x}}{2}=3x\)

Average money of three persons = 12000

Therefore, total money to thee 12000 × 3

\(\displaystyle 3x+\frac{{3x}}{2}+x=12000\times 3\)

\(\displaystyle \frac{{6x+3x+2x}}{2}=36000\)

3x=\(\displaystyle 3x=\frac{{3\times 7200}}{{11}}\)

Therefore, x \(\displaystyle \frac{{36000\times 2}}{{11}}=\frac{{72000}}{{11}}\)

Now, money of A

=\(\displaystyle 3x=3\times \frac{{72000}}{{11}}=\frac{{216000}}{{11}}\)

Answer is (d)

Let the weight of fresh grapes be x.

Quantity of water in it = \(\displaystyle \frac{{80}}{{100}}\times x=\frac{{4x}}{5}\)

Quantity of pulp in it = \(\displaystyle x-\frac{{4x}}{5}=\frac{x}{5}\)

Quantity of water in 500 kg dry grapes = \(\displaystyle \frac{{10}}{{100}}\times 500=50kg\)

Therefore, quantity of pulp in it = (500 – 50) = 450 kg

\(\displaystyle \frac{x}{5}=450\)

x = 2250 kg

Answer is (b)

Second number = \(\displaystyle \frac{1}{4}\times 2960=740\)

Let the first number be x.

\(\displaystyle \frac{5}{9}x=\frac{{25}}{{100}}\times 740\)

\(\displaystyle x=\frac{9}{5}\times \frac{1}{4}\times 740=333\)

30% of 1st number = \(\displaystyle \frac{{30}}{{100}}\times 333=99.9\)

Answer is (c)

Total number of students = 480

Percentage of total students passed

75% of total students =\(\displaystyle \frac{{75\times 480}}{{100}}=360\) students

Now, using the condition from the question,

Let the number of boys be x.

Then, 70% of x + 85% of (480 – x) = 360

\(\displaystyle \Rightarrow \)\(\displaystyle \frac{{75\times x}}{{100}}+\frac{{85\times (480-x}}{{100}}=360\)

\(\displaystyle \Rightarrow \)70x – 85x + 40800 = 36000

\(\displaystyle \Rightarrow \)40800 – 36000 = 85x – 70x

\(\displaystyle \Rightarrow \)x = \(\displaystyle \frac{{4800}}{{15}}=320\)

Therefore, there are 320 boys who appeared for the examination.

Answer is (c)

Boys in class 4 = \(\displaystyle \frac{{60}}{{100}}\times 6x=\frac{{360x}}{{100}}\)

Boys in class 5 = \(\displaystyle \frac{{52}}{{100}}\times 11x=\frac{{572x}}{{100}}\)

So total boys = \(\displaystyle \frac{{360x}}{{100}}+\frac{{572x}}{{100}}=\frac{{932x}}{{100}}=9.32x\)

% of boys = \(\displaystyle \frac{{9.32x}}{{17x}}\times 100=54.8\%\)