Exams

Sony and her brother's age sum is 31
Let Sony's mother's age be 'x'.
Now the conditions given for both of their ages related to their mom is
1/5(x-15) + 3/5(x-10) = 31
x-15 + 3x-30 = 155
4x-45 = 155
4x = 200
x = 50
So, Mother's age = 50.

Cross verification : 15 years ago age = 35 => Sony age = 7
10 years ago age = 40 => bro age = 24

Sum = 24 + 7 = 31.

Deoxyribose, which is a pentose, and a phosphate group are the two molecules together form the two sides of the DNA i.e, A sugar (deoxyribose) and a phosphate.

DNA is a double-stranded molecule twisted into a helix (think of a spiral staircase). Each spiraling strand, comprised of a sugar-phosphate backbone and attached bases, is connected to a complementary strand by non-covalent hydrogen bonding between paired bases. The bases are adenine (A), thymine (T), cytosine (C) and guanine (G). A and T are connected by two hydrogen bonds. G and C are connected by three hydrogen bonds.

Except Rock color, all other Graded bedding, Ripple marks and Mud cracks are sedimentary structures.

Let the value to be find be 'x'.

 
Sum of individual column value = 14

 
C1 = 7 + 2 + 1 + 4 = 14
C2 = 3 + 8 + 1 + 2 = 14
C3 = 6 + 5 + 2 + 1 = 14

C4 = 2 + 4 + 4 + x = 14

x = 14 - 10

x = 4

Hence, the missing number is '4'.

A computer program is a collection of instructions that performs a specific task when executed by a computer

C2H6O is a Non-electrolyte.

An electrolyte is a compound that conducts an electric current when it is in an aqueous solution or melted. In order to conduct a current, a substance must contain mobile ions that can move from one electrode to the other. All ionic compounds are electrolytes. When ionic compounds dissolve, they break apart into ions which are then able to conduct a current ( conductivity ). Even insoluble ionic compounds such as CaCO 3 are electrolytes because they can conduct a current in the molten (melted) state.

A nonelectrolyte is a compound that does not conduct an electric current in either aqueous solution or in the molten state. Many molecular compounds, such as sugar or ethanol, are nonelectrolytes. When these compounds dissolve in water, they do not produce ions.

Electrolytes are of 3 types ---- Strong Electrolytes, Weak Electrolytes and Non Electrolytes.

Strong Electrolytes ---- Compounds which completely dissolves. ( NaCl, Na2Co3, HCl )

Weak Electrolytes ----- Compounds which do not completely dissolves.

Non Electrolytes ------ Compounds which do not dissolves at all.