Post of the Week
Mathematics helps us to solve our daily life problems. Our day will not pass without solving many of the mathematics problem and without doing math calculations. Today I am going to post some of the real life problems which can be solved by mathematics. Many of these problems we may have come across in our daily life.
Try not to use calculator while solving these math questions. It will be great if you can solve these problems in your mind without even using pen or pencil. These math problems requires knowledge of basic mathematical operations. Answers to these Math riddles are given at the end of this post. Please do put your answers in the comment section of this post.
Q1. Sudeep walks at 6km/h for 3hr and 10km/h for 5hr. What is his average speed?
Q2. If sum of two numbers is -3 and their product is 12. Find the numbers?
Q3. How many multiples of 5 lies between 12 and 254?
Q4. The ratio between the speeds of two trains is 8: 9. If one train runs 720 km in 8 hours, then what is the speed of the second train?
Q5. If a person bought a TV for Rs. 35,000. and sold it after two years for Rs 27000. Find the loss or gain on his deal?
Q6. Rahul’s mother is 25 years older than him, the product of their ages 5 years from now will be 350. Find their present ages.
Q7. Find the least number which is exactly divisible each of the numbers 12, 16 and 24.
Q8. One liter of petrol costs Rs. 30. What is cost of 35 liters of petrol?
Q9. Find the area of a square whose each side is 14m.
Q10. An airplane covers 5456 km in an hour how much distance will it cover in 5 hours.
These Fun Brain Teasers are part of Fun Math Brain Teasers. Below are the next and previous Math Brain Teasers in this series.
Previous Math Brain Teasers: Basic Quick Maths Riddles for Kids with answers
Next Math Brain Teasers: What Comes Next In The Sequence Riddles With Answers
Hidden answers of these mathematical problems is given below. Do select the text between the numbers to watch out for the corresponding answer.
A1. 2 km/h
Average speed = total distance / total time
Average speed = 10+6/8= 16/8
Avg speed = 2km/h
A2. x=3,4. y=4,3
XY= 12, x=12/y , substituting value of x in (1) we have.
(y-4) ( y-3) =0
Y =4, y=3 and x=3,4.
First number that is multiple of 5 between 12 and 254 = 15,
Last number that is multiple of 5 between 12 and 254 = 250.
So here ,
a ( initial term)= 15 ,
an= 250, d ( common difference)= 5 according to A.P formula
an= a+ (n-1)d
235 /5 = n-1, n-1= 47
n=47+1=48, Hence there 48 multiples of 5 that lies between 12 and 254,
Speed of first train / speed of second train = 8/9
720 /9/ speed of second train = 8/9
80/ speed of second train = 8/9
Speed of second train= 9x80/8= 90 km /h.
A5. Loss= 8000
Cost Price (C.P) of TV= 35000
Selling Price (S.P) of TV= 27000
We know if C.P > S.P its a loss
Therefore Loss= C.P- S.P= 35000- 27000= 8000 RS.
A6 . 5 and 30
Let us suppose Rahul’s present age = x
Mother’s age = x+25
Five years from now , Rahul age = x+5
Mother age = x+30
x²+5x+30x+ 150 = 350
x²+35x+150 = 350
x²+35x -200 =0
x(x+40) – 5( x+40)=0
x=-40, x=5, Taking only positive value , we have
Rahul age is 5 years and mother’s present age is 30 years.
Least number divisible by 12, 16 and 24.= L.C.M of 12, 16 and 24= 48.
Cost of One liter of petrol = 30
Cost of 35 liter of petrol = 30x 35= 1050
A9. 196 sqm
Side of square = 14m
Area of square = side x side
Area= 14x14= 196 sq m
Q10. 27280 km
Distance covered by airplane in one hour = 5456 km
Distance covered by airplane in 5 hours = 5456 x 5
= 27280 km