Answer:
<em>C</em><em> </em><em>.</em><em> </em><em>the</em><em> </em><em>dramatic</em><em> </em><em>scenery</em><em> </em><em>created</em><em> </em><em>by</em><em> </em><em>volcanic</em><em> </em><em>eruptions</em><em> </em><em>attracts</em><em> </em><em>tourists</em><em>. </em>
Answer : The ages of the brother and sister are, 10 and 16 years respectively.
Solution :
Let the age of brother be 'x' and the age of sister be 'y'
There are two equations formed which are,
x + y = 26 ..........(1)
3y - 4x = 8 ..........(2)
First we have to multiple equation (1) by 4 and then added equation (1) and (2), we get the value of 'y'.
Now put the value of 'y' in equation (2), we get the value of 'x'
3(16) - 4x = 8
4x = 40
x = 10
The age of brother = x = 10 years
The age of sister = y = 16 years
Therefore, the ages of the brother and sister are, 10 and 16 years respectively.
An Olympic decoration is granted to effective contenders at one of the Olympic Amusements. There are three classes of decoration: gold, granted to the victor; silver, granted to the first sprinter up; and bronze, granted to the second sprinter up.
Answer:
2.23M
Explanation:
Molarity of a solution is calculated thus
Molarity = number of moles (n) ÷ volume (V)
According to this question, 4.11g of Zn metal was used in order to reach a volume of EDTA solution of 28.26 mL.
28.26mL = 28.26/1000
= 0.02826L
Using mole = mass/molar mass to calculate no. of moles of Zn
Mole = 4.11/65.4
mole = 0.0628mol
Molarity = 0.0628 ÷ 0.02826
Molarity = 2.23M
The concentration of the EDTA solution used is 2.23M
