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vIf 2 apples each weight 150 grams cost Rs.15, what would be the cost of 2 and 3/4 kg of apples?

This is an application based question. ( Unitary Method)

Q.No	Step	Q	Remarks
1	Step: 1	What is the data given in the Problem	Cost of 2 apples each weight 150 grams cost Rs. 15
		Deduction : total weight of apples= 300 grams	300 grams cost Rs. 15
	Step 2	To find the cost of 2 ¾ kg of apples
	Step 3	Is any conversion required?	Yes convert kg into grams Because the question asks for cost
	Step 4	Formula	Unitary Method, find the cost of 100 grams and multiply with the cost of 2750 grams
			100 grams ------ Rs. 5 2750 grams------X
			100 *  x = 2750 x 5 X = ( 2750 x 5 ) / 100 =  13750/ 100 = Rs.137.50
	Step 5	Answer:  Therefore cost of 2 ¾ kg of apples=	Rs. 137.50

Q.2 Solution:

A car is moving at an average speed of 36 and 4/5 km/h.

How much distance will it cover in 7 ½ hours?

Sol.

Distance covered by the car in 1 hour= 36 and4/5 km

Distance covered by the car in 7 ½ hours = 276 km

Distance covered by the car in 1 hour= 36and 4/5 hours = 154/ 5

km.Distance covered by the car in 7 1/2 = 15 / 2

ie =(184 /5) *(15/ 2)= 276 km.

Hence, the required distance is 276 km.

Q.3. The sum of two consecutive numbers is 53. Find the numbers

To do this there are two methods:

Sol.

Let one number be x. Then, the next consecutive numberis x + 1. It is given that the sum of two consecutivenumbers is 53. So, we obtain the following equation :x + (x + 1) = 53

2x + 1 = 53

2x = 53 -1  [On transposing 1 on R.H.S.]

2x/2 = 52/2 = 252  [Dividing both sides by 2]

x = 26

One number = 26

Another number = 26 + 1 = 27.

Second Method:

Sum of two consecutive numbers = 53

Ie 53/ 2 = 26.5

Since it is two consecutive numbers  should be 26 and 27 =  (ie  26 + 27 = 53)

Twelve years hence a man will be four times as he was twelve years ago, then his present age is :

Let the present age be x

x-12 = 4( x+12)

x – 12 = 4x + 48

or 4x – x = 48 +12

3x = 60

Hence x 60/3 = 20 years ( as on today) Answer

Two men work for 8 hours  a day to complete the project in 40 days. If  one man has to do the same task working for 12 hours a day, how long ( how many days) will he take to complete the task?

Solution:

One man 8 hours x 40 = 320 hours + 320 hours = 640 hours

640/12 = 53.33  days.