Sarah went to a grocery shop. There is a sales chart.

Sarah bought 4 carton potatoes and 1 cabbage. If she gave $10, how much money she got back?

A box contains 12 marbles of three different colors. Green, yellow and blue- 4 each.

If you were to close your eyes and pick them at random, how many marbles must you take out to be sure that there are at least two of one color among the marbles picked out?


Answer:

In the first three pickings you may get 1 of each color. in the 4 th pick there will be at least two of one color.
So, the answer is 4.

In a two digit number, the ten’s digit is three times the units digit.

A group consists of 50 students. Out of these 20 are girls .There are 10 Australian students. Out of 50 students, 25 students like cricket.
What is the probability of selecting an Australian girl who likes cricket?




Hint:

Probability of selecting a girl= 20/50
Probability of selecting an Australian student = 10/50
Probability of a student like cricket=25/50

Therefore the the probability of selecting an Australian girl who likes cricket= (20/50 )(10/50)(25/50) = 1/25 =0.25

The following is the net representation of a cube.


How will you place the letters L, A, F on the figure so that it should spell LEAF around the sides of the cube?

Today we have a questions on percentage.


Ana is working in a restaurant as a bearer.

As a penalty Ana’s wages were decreased by 50%.
After one month the reduced wages were increased by 50%.

Find her loss.

Hint: The salary increased is the 50% of the decreased salary.




Answer:








New salary is 50+25=75
Therefore loss=25%

Today we have a problem on triangle

Hint:

Since AB=BC, angle C= angle A (Angles opposite to equal sides are equal)

Also, Sum of the angles is 180 º

Answer

55 º

John has a rectangular lawn of dimensions 50 meter by 40 meter.

It has two roads each 2 meter wide running in the middle of it one parallel to the length and one parallel to the breadth. He wants to tar the road.

Find area of the roads to be tarred.

Hint:

We have two roads to be tarred. One is horizontal and the other is vertical.

So, area to be tarred is the area of the two roads which are rectangular in shape.

Area of a rectangle is length x breadth.

Area of the horizontal road = 2 x 50=100 sq.m

Area of the vertical road = 2 x 40=80 sq.m

So,the total are of the two roads=100+80=180 sq.m

But, the roads are crossing at the middle. It is a square portion of sides 2m by 2m in dimensions and we can see that two times we added that area. So, we should subtract that area from the total area of the two rectangular roads.

Area of the square portion is 2 x 2=4 sq.m

Therefore, the area to be tarred = Total area of the two rectangles - The common area

Ans: 176 sq.m

The average temperature of for Monday, Tuesday and Wednesday was 30ºC.
The average temperature for Tuesday, Wednesday and Thursday was 29º C. The Temperature on Thursday was 32º C.

What was the temperature on Monday?



Hint:

Total temperature on Mon,Tue and Wed = 30ºC*3 = 90ºC
Total temperature on Tue,Wed and Thu = 29ºC*3 = 87ºC

Total temperature on Tue and Wed = Total temperature on Tue, Wed and Thu -Temperature on Thu = 87ºC-32ºC= 55ºC

Now, Temperature on Monday can be calculated as follows

Temperature on Monday = Total temperature on Mon,Tue and Wed-Total temperature on Tue and Wed

Ans: 35ºC

Can you find the biggest number you can make with three 3s?

Today let’s discuss one problem from geometry.

I‘ll ask you one question. What is the area of a right triangle with sides 4cm 5cm and 9cm? Before trying to answer, please read the question once more.




Answer
It is not possible to make a triangle with the given measurements.
In a triangle, the sum of the two sides will be greater than the third side. Here in this case sum of two sides 4cm+5cm=9cm, which is not greater than the third side of measurement 9cm.

“The sum of seven and five is thirteen” or “the sum of five and seven is thirteen”-according to mathematics rule, which is more correct?



Answer:
Both are wrong