Sign up now
to enroll in courses, follow best educators, interact with the community and track your progress.
Overview Lesson
1,247 plays


Varsha Pujari
I talk a lot, I like reading novels, playing tennis,watching TV, learning & trying out new things in life & love being around my dogs

Unacademy user
aap pahle har ek question ka ans bol di jiye aur uske saath uska details di jiye.

  2. AVERAGES Sum of all items in the group Number of items in the groujp Ex: Suppose there are 30 students in class: Avg height = sum of heights of all students Number of students in class

  3. Average is also called mean value If the value of each item is increased by a same value 'x' then the avg of the group of items also increases by x'. If a value of each item is multiplied by the same value 'x' then the avg of a group of items also gets multiplied by 'x'.

  4. WEIGHTED AVERAGE : it's the average of two different groups. Ex: avg height of class 'a' of strength 30 -150 avg height of class 'b' of strength 20 -100 Weighted avg = 30x150 + 20x100 = 130 3020

  5. MIXTURES Weighted avg can be calculated for any mixture. Suppose: q1- quantity of an item of quality p1 q2 quantity of another item of quality p2 Weighted avg, p - p1q1 + p2q2 q1+q2

  6. ALLIGATIONS Rule of alligation: q2 p-p1 quantity of cheaper quantity of dearer rate of dearer-average rate average rate-rate of cheaper

  7. Dearer price Cheaper price AVERAGE PRICE Avg price-Chper priceDearer price-avg price

  8. Suppose a container contains 'x' units of liquid from which 'y' units are taken out and replaced by water. Then after 'n' operations: Quantity of pure liquid = (x-y)n = k(say)