NCERT Solutions for Class 8 Maths - Decimals (Exercise 8.3 and 8.4)

Exercise 8.3

Q2. Rashid spent Rs 35.75 for Maths book and Rs 32.60 for Science book. Find the total amount spent by Rashid.
Ans: Money spent for Maths book = Rs 35.75
Money spent for Science book = Rs 32.60
Total money spent = Rs 35.75 + Rs 32.60 = Rs 68.35
Therefore, total money spent by Rashid is Rs 68.35.

Q3. Radhika’s mother have her Rs10.50 and her father gave her Rs15.80. Find the total amount given to Radhika by the parents.
Ans: Money given by mother = Rs 10.50
Money given by father = Rs 15.80
Total money received by Radha = Rs 10.50 + Rs 15.80 = Rs 26.30
Therefore, the total money received by Radha is Rs 26.30.

Q4. Nasreen bought 3 m 20 cm cloth for her shirt and 2 m 5 cm cloth for her trouser. Find the total length of cloth bought by her.
Ans: Cloth bought for shirt = 3 m 20 cm = 3.20 m
Cloth bought for trouser = 2 m 5 cm = 2.05 m
Total length of cloth bought by Nasreen = 3.20 + 2.05 = 5.25 m
Therefore, the total length of cloth bought by Nasreen is 5.25 m

Q5. Naresh walked 2 km 35 m in the morning and 1 km 7 m in the evening. How much distance did he walk in all?
Ans: Distance travelled in morning = 2 km 35 m = 2.035 km
Distance travelled in evening = 1 km 7 m = 1.007 km
Total distance travelled = 2.035 + 1.007 = 3.042 km
Therefore, the total distance travelled by Naresh is 3.042 km.

Q6. Sunita travelled 15 km 268 m by bus, 7 km 7 m by car and 500 m by foot in order to reach her school. How far is her school from her residence?
Ans: Distance travelled by bus = 15 km 268 m = 15.268 km
Distance travelled by car = 7 km 7 m = 7.007 km
Distance travelled on foot = 500 m = 0.500 km
Total distance travelled = 15.268 + 7.007 + 0.500 = 22.775 km
Therefore, total distance travelled by Sunita is 22.775 km.

Q7. Ravi purchases 5 kg 400 g rice, 2 kg 20 g sugar and 10 kg 850 g flour. Find the total weight of his purchases.
Ans: Weight of Rice = 5 kg 400 g = 5.400 kg
Weight of Sugar = 2 kg 20 g = 2.020 kg
Weight of Flour = 10 kg 850 g = 10.850 kg
Total weight = 5.400 + 2.020 + 10.850 = 18.270 kg
Therefore, the total weight of Ravi’s purchase = 18.270 kg.

Exercise 8.4

Q2. Find the value of:
(a) 9.756 – 6.28
(b) 21.05 – 15.27
(c) 18.5 – 6.79
(d) 11.6 – 9.847
Ans:

Q3. Raju bought a book of Rs 35.65. He gave Rs 50 to the shopkeeper. How much money did he get back from the shopkeeper?
Ans: Total amount given to shopkeeper = Rs50
Cost of book = Rs35.65
Amount left = Rs50.00 – Rs35.65
= Rs 14.35
Therefore, Raju got back Rs14.35 from the shopkeeper.

Q4. Rani had Rs18.50. She bought one ice-cream for Rs11.75. How much money does she have now
Ans: Total money = Rs18.50
Cost of Ice-cream = Rs11.75
Amount left = Rs18.50 – Rs11.75
= Rs6.75
Therefore, Rani has Rs6.75 now.

Q5. 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?
Ans: Total length of cloth = 20 m 5 cm = 20.05 m
Length of cloth used = 4 m 50 cm = 4.50 m
Remaining cloth = 20.05 m – 4.50 m = 15.55 m
Therefore, 15.55 m of cloth is left with Tina.

Q6. Namita travels 20 km 50 m every day. Out of this she travels 10 km 200 m by bus and the rest by auto. How much distance does she travel by auto?
Ans: Total distance travel = 20 km 50 m = 20.050 km
Distance travelled by bus = 10 km 200 m = 10.200 km
Distance travelled by auto = 20.050 – 10.200 = 9.850 km
Therefore, 9.850 km distance travels by auto.

Q7. Aakash bought vegetables weighing 10 kg. Out of this 3 kg 500 g in onions, 2 kg 75 g is tomatoes and the rest is potatoes. What is the weight of the potatoes?
Ans: Weight of onions = 3 kg 500 g = 3.500 kg
Weight of tomatoes = 2 kg 75 g = 2.075 kg
Total weight of onions and tomatoes = 3.500 + 2.075 = 5.575 kg
Therefore, weight of potatoes = 10.000 – 5.575 = 4.425 kg
Thus, the weight of potatoes is 4.425 kg