The average speed in km per hour is shown by:

Average speed = Total distance travelled / Time taken in hours

Hence the time given is minutes, we need to first 

52 minutes = 52 / 60 hours = 0.87 hours

Therefore, Average speed is

Average speed = 64 km / 0.87 hours = 73.56 km/hr

that is, the average speed of the car was 73.56 km/hr.

Please find the attachment.

Average = total sum of all items / number of items

Total sum   of Income ( items)= 4500 +3550+4260+ 4880 = Rs.17190

Total number of Items = 4 ( months)

 Average = 17190 /4 = Rs. 4297.50

let a number be d. additive inverse of a number is also a number. the additive inverse of a number b will be -b.  lets understand what an additive inverse is with the above example,

additive inverse of a number b is the number that, when added to b , yields zero. that is,

b + additive inverse of b= 0

b + (-b)= 0                          (as the additive inverse of b is -b)

so here -b satisfy the condition of getting an answer equal to 0.

in simple words, additive inverse simply means changing the sign of the number and adding it to the original number to get an answer equal to 0.

additive inverse is the number that is added to a given number to make the sum zero.

60% of 2nd Number = 25% of 1st Number

Let 2nd number be y and 1st number be x

60y/100 = 25x/100

Therefore, y = 5x/12

Hence, 80% of y = 80y/100 = (80×5x)/(100×12) = x/3 or 33.33% of x

See the Answer

• Area of Rectangle = Length x Breadth

Ans There are 4 50Rs. notes and 5 10 Rs. notes.

Explanation: Let, the no. of  50 Rs. notes be x.   So, no. of 10 Rs. notes = (x+1).

Thus the total amount = Rs. [50x + 10(x+1)] = Rs. (60x + 10)

By the prob, 60 x + 10 = 240 

Solving, we get, x = 4 . So, x+1 = 5

Ans. The Sum of money is Rs. 5650

Explanation: Here, we see, interest in (6-4) = 2 years = Rs. (8362 - 7458) = Rs. 904.

So, interest in 4 years = Rs. 904 x 2 = Rs. 1808.

Hence, the sum of money = Amount in 4 years - Interest in 4 years = Rs. (7458 - 1808) = Rs. 5650.

INITIAL CONCENTRATION = 125 LITRES

REPLACED CONCENTRATION = 25 LITRES

 FINAL CONCENTRATION = INITIAL (1- REPLACED/INITIAL)^3                  [AS THIS METHOD WAS DONE FOR 3 TIMES]

                                            = 125 ( 1 - 25/125)^3

                                           = 125 ( 100/125)^3

                           ON SOLVING THIS YOU WILL GET   64 LITRES......WHICH IS MILK 

       AND REMAINING   61 LITRES WILL BE WATER .