Find the value of the given expression.

$$ \sqrt { 20-{ \sqrt { 20- \sqrt { 20- \sqrt { 20- .....∞}}}}} $$

ABCD is a cycle quadrilateral and BC is diameter of the related circle on which A and D also lie. ∠BCA =19⁰ and ∠CAD=32⁰. What is the measure of ∠ACD?

Suresh, Dinesh and Ramesh became partners in a business by investing money in the ratio of 3 : 6 : 8. If their investments is increased by 5%, 15% and 20%, respectively, then what will be the ratio of their profits for one year? 

Find the standard deviation of the following data (rounded off to two decimal places). 5, 3, 4, 7 

The ratio of marks obtained by Rajesh, Rakesh and Ramesh in an exam is 2 : 4 : 9. What are the marks obtained by Rakesh and Ramesh, if Rajesh scored 30 marks in the exam? 

Rewa has some hens and some goats. If the total number of animal heads is 100 and the total number of animal feet is 348, then what is the total number of goats with Rewa? 

A hemispherical bowl of internal radius 18 cm is full of liquid. This liquid is to be filled in cylindrical bottles each of radius 3 cm and height 6 cm. How many bottles are required to empty the bowl

Two candidates contested an election. One of them got 64% of the votes and won by 434 votes. What was the total number of votes polled?