Answer:Robert's minimum age is 11 years.
Step-by-step explanation:
Let x represent George's age.
Let y represent Edward's age.
Let z represent Robert's age.
George is twice as old as Edward. It means that
x = 2y
Edward's age exceeds Robert's age by 4 years. It means that
z = y - 4
If the sum of the three ages is at least 56 years, it means that
x + y + z ≥ 56 - - - - - - - - - - 1
Substituting x = 2y and z = y - 4 into equation 1, it becomes
2y + y + y - 4 ≥ 56
4y - 4 ≥ 56
4y ≥ 56 + 4
y ≥ 60/4
y ≥ 15
z = y - 4 = 15 - 4
z ≥ 11
All the numbers in this range can be written as
with
and
. Construct a table like so (see attached; apparently the environment for constructing tables isn't supported on this site...)
so that each entry in the table corresponds to the sum of the tens digit (row) and the ones digit (column). Now, you want to find the numbers whose digits add to perfect squares, which occurs when the sum of the digits is either of 1, 4, 9, or 16. You'll notice that this happens along some diagonals.
For each number that occupies an entire diagonal in the table, it's easy to see that that number
shows up
times in the table, so there is one instance of 1, four of 4, and nine of 9. Meanwhile, 16 shows up only twice due to the constraints of the table.
So there are 16 instances of two digit numbers between 10 and 92 whose digits add to perfect squares.
Answer:
Option B and D are correct
Step-by-step explanation:
Exponential functions are really useful in the real world situation. They can be used to solve following
a) Population Models
b) Determination of area and perimeters
c) Determine time related things such as half life, time of happening of an event etc.
d) Useful for solving financial problems such as computing investments etc.
Hence, option B and D
Answer:
The cafeteria provides three meals per day.
<u>Reason 1</u>
Yes, they vary directly
As number of days increases ,Total number of meals i.e
1st day ⇒ 3
2nd day⇒6
3 rd day⇒9
4th day⇒12
......................
.........................
increases.
Total number of Meals = k×Number of days
But there is another possibility also
<u>Reason 2</u>
1 st day ⇒ 3
2nd day ⇒3
3rd day⇒ 3
.....................
.....................
As you can see from the above expression On each day number of meals is
constant.
So we can say that ,
On each Day=Constant amount of meal=3
So, there is no Proportionality between Days and Meal.
Answer:
5.15
Step-by-step explanation:
17.51 / 3.4 = 5.15