Answer and Explanation:
To find : Perform the indicated operations?
Solution :
Modular math is defined as

or 
Where, A is the dividend
B is the divisor
Q is the quotient
R is the remainder
The solution is 
Now, We perform same in every case
1) 
We can direct add the term,

Now, we divide 15 by 5 and see the remainder

Remainder is 0.
So, 
2) 
We can direct subtract the term,

Now, we divide -4 by 12 and see the remainder

Remainder is 8.
So, 
3) 
We can direct multiply the term,

Now, we divide 12 by 5 and see the remainder

Remainder is 2.
So, 
4) 
We can direct divide the term,

Now, we divide 0.5 by 5 and see the remainder

Remainder is 0.5.
So, 
Answer:
First you have to multiply the number by the percent.
Then, divide the answer by 100, and make sure you move decimal point two places to the left.
Last, you must round to the desired precision.
Answer:
Andy is 4 years old.
Step-by-step explanation:
Given:
Ruth age = 10
We need to find Andy age.
Let the age of Andy be x.
Also given Andy is two-fifths of Ruth's age.
Expressing the above statement in expression form we get

Hence Andy is 4 years old.
Answer:
The option D is the answer
Answer: 63
Explanation: The sum of the two percentages is 45%. Thus the sum of the 28 and 35 (63) is equal to 45% of the number.
If you needed to check your work, you could work out the number to be 140 and simply multiply by 0.45.