Answer the following questions by selecting the correct/most appropriate option.

What is the missing number in the pattern given below?
1, 6, 15, ____________, 45, 66, 91

Evaluate:
$$\frac{12\times272\div16+264}{1256\div32-26.25}$$​=?

​$$60\%\text{ of }4500-\frac{9^3\times48}{\sqrt{256}}-20\%\text{ of }95=x$$​. Find the value of x ?

What is the value of ' x ' in the following equation?
​$$11^2+1.1^2+0.11^2+0.011^2=x$$​​

The value of $$\frac{5}{5+\frac{1}{4-\frac{1}{\frac78}}}+\frac{7}{107}$$​ is:

If 88% of 1110 + 24% of 630 - 3x = 282, then x is equal to:

In a school, 180 students are studying in the 9^th class. Among them, 35% are rich and others are poor. There are 80 girls in the class, of whom 65% are poor. How many rich boys are there in the class?

What should replace '?' in the equation given below?
​$$5\frac{10}{17}\div 7\frac{12}{34}-\frac{3}{25}=(?)^2$$​​

​$$\sqrt{201\frac{49}{100000}+49\frac{1}{10000}-\frac{5}{1000}+6\frac{45}{10000}}=x$$​
Find the approximate value of $$x^2$$​ ?

Find the HCF of 2.8, 11.2 and 0.84 .

Evaluate:
$$\frac{12\times272\div16+264}{1256\div32-26.25}$$​=?