Chapter 7: Decimals – Exercise 7.9

Question: 1

Subtract:

Solution:

1. 46.23 – 37.5

= 8.73

1. 128.40 - 53.05

= 75.35

1. 45.03 - 27.80

= 17.23

1. 23.930 - 5.946

17.984

Question: 2

Subtract:

Solution:

1. 9.756 –  6.280

= 3.476

1. 21.05 – 15.27

= 5.78

1. 18.50 – 6.79

= 11.71

1. 48.10 – 0.37

= 47.73

1. 108.032 –  86.800

= 21.232

1. 91.001 – 72.900

= 18.101

1. 100.0 –  26.32

= 73.68

Question: 3

The sum of two numbers is 100. If one of them is 78.01. Find the other one?

Solution:

One number is 78.01

Suppose the other number is x

The sum of these numbers is 100

Therefore, 78.01 + x = 100

= x = 100 -78.01

= x = 21.99

The other number is 21.99

Question: 4

Waheeda’s school is at a distance 5 km 350 m from her house. She travels 1 km 70 m on foot and the rest she travels by bus. How much distance does she travel by bus?

Solution:

Distance travelled on foot = 1 km 70 m

Suppose the distance travelled by bus = x km

Total distance of school from residence = 5km 350 m = 5.350 km

So, 1.070 +x = 5.350

= x= 5.350 – 1.070

= x = 4.280 km

Therefore, distance travelled by bus is 4.280 km

Question: 5

Raju bought a book of Rs.35.65. he gave Rs.50.35 to the shopkeeper. How much money did he pay back to the shopkeeper?

Solution:

Price of the book = Rs. 365

Amount given to the shopkeeper = Rs50

Therefore, balance returned by the shopkeeper = Rs. (50 - 35.65)

= Rs. 14.35

Question: 6

Raju bought a water melon weighing 5 kg 200g. Out of this she gave 2 kg 750 g to her neighbor. What is the weight of the watermelon left with ruby?

Solution:

Weight of the watermelon when bought = 5 kg 200g = 5.200 kg

Weight of the watermelon given to the neighbor = 2 kg 750 g = 2.750 kg

Therefore, weight of the watermelon left with ruby = weight of the watermelon when bought – weight of the watermelon when given to the neighbor

= (5.200 - 2.750) kg

= 2.450 kg

So, the weight of the water melon left with ruby = 2.450 kg

Question: 7

Victor drove 89.05 km on Saturday and 73.9 km on Sunday. How many kilometers did he drove more on Saturday?

Solution:

Distance travelled on Saturday = 89.050 km

Distance travelled on Sunday = 73.9 km

Subtracting the distance travelled on Sunday from the distance travelled on Saturday = 89.050 – 73.9 km

= 15.15 km

Therefore, victor drove 15.15km more on Saturday.

Question: 8

Raju bought a book of Rs.35.65. he gave Rs.50.35 to the shopkeeper. How much money did he pay back to the shopkeeper?

Solution:

Price of the book = Rs. 365

Amount given to the shopkeeper = Rs50

Therefore, balance returned by the shopkeeper = Rs. (50 - 35.65)

= Rs.14.35

Question: 9

Gopal travelled 125.5 km by bus, 14.25 km by pony and the rest of the distance to kedarnath on foot. If he covered a total distance of 150 km, how much did he travel on foot?

Solution:

Distance travelled by bus = 125.5 km

Distance travelled by pony = 14.25 km

Suppose the distance travelled on foot = x

Total distance = 150 km = distance travelled by bus + distance travelled on pony + distance travelled travelled on foot

= 150 = 125.5 + 14.25 + x

= 150 = 139.75 + x

= x = 10.25 km

Therefore, distance travelled on foot= 10.25 km

Question: 10

Tina had 20 m 5 cm long cloth. She cuts 4 m 50 cm length of cloth from this for making a curtain. How much cloth is left with her?

Solution:

Length of cloth originally = 20 m 5 cm = 2.05 m

Length of cloth cut for curtain = 4m 50 cm = 4.50 m

Therefore, length of cloth left with tina = length of cloth originally – length of cloth cut for curtain

= 20.05 – 4.50 m

= 15.55 m

Length of the cloth left with tina = 15.55 m

Question: 11

Vineeta bought a book of Rs. 18.9, a pen of Rs. 8.50 and some papers for Rs. 5.05. She gave fifty rupee to the shopkeeper. How much balance did she get back?

Solution:

Price of the book = Rs. 18.90

Price of the pen = Rs 8.50

Price of the paper = Rs. 5.05

Total price of three items = Rs(18.90 + 8.50 + 5.05)

= Rs 32.45

Total amount given to the shopkeeper = Rs 50

Balance received = Rs (50 - 32.45)

= Rs. 17.55

Question: 12

Tanuj walked 8.62 km on Monday, 7.05 km on Tuesday, and some distance on Wednesday. If he walked 21.01 km in three days, how much distance did he walk on Wednesday?

Solution:

Distance travelled on Monday = 8.62 km

Distance travelled on Tuesday = 7.05 km

Suppose the distance travelled on Wednesday = x km

Total distance covered =

21.01 = 8.62 + 7.05 + x

= x = 21.01 – 15.67

= x = 5.34

Therefore, Tanuj walked 5.34 km on Wednesday.