Question

6. Find the average of first ten odd numbers.

7. Find the average of 1 hour 25 minutes, 2 hours 40 minutes, 3 hours 35 minutes and 4 hours.

8. Ryan covered a distance of 42 km in 3 hrs and a further distance of 44 km in 4 hrs. Find his average speed.

9. The average of 20 numbers is 75. The number 86 was incorrectly read as 68 while calculating. Find the correct average.

10. The total sales in a coffee shop for a week are $ 9723.00. What is the average sale per day?
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Answer 1

Answer:

6.The numbers are A. P

1,3,5........,19

where a=1, l=19

Now using the formula, sum of nth term=n/2{a+l},

we get

sum=10/2{1+19}

=100

Now average =100/10

=10

7.average ={(60+25) +(120+40) +(180+35) +240}/4

= 175

8.average speed=total distance / total time

= 44+42/7

=12.3 km/hr

9.Let sum be x

Now, x/20=75

x=1500

Now, 86-68=18

then, real average=1500+18/20

=75.9

10.average sale per day=sale/total days

=9723/7

=$131.86 per day