Selina Concise Class 6 Math Chapter 13 Unitary Method Exercise 13A Solution
EXERCISE 13A
(1) (i) Cost of 25 identical articles = Rs 1750
∴ Cost of 1 identical article = Rs (1750/25) = 70
(ii) Cost of 13 articles = Rs (70 × 13) = Rs 910
(2) (i) In 5 litres petrol the bike travels = 330 km
∴ In 1 litre petrol the bike travels = (330/5) = 66 km
(ii) In 2.5 litres petrol the bike travels = (66 × 2.5) = 165 km
(3) The cost of 12 (1 dozen) soap = Rs 460.80
(i) Cost of 1 soap = Rs (460.80/12) = Rs 38.40
(ii) Cost of 15 soaps = Rs (38.40 × 15) =Rs 576
(iii) Cost of 36 (3 dozen) soaps = Rs (38.40 × 36) = Rs 1382.40
(4) Rs 105 is cost of 35 envelops
∴ Rs 1 is cost of (35/105) = 1/3 envelops
∴ Rs 90 is cost of = (90/3) = 30 envelops.
(5) Cost of 8 cans juice is Rs 280
∴ Cost of 1 can juice = Rs (280/8) = Rs 35
∴ Cost of 6 can juice = Rs (35 × 6) = Rs 210
(6) In Rs 378 bought the juice of = 9 cans
∴ In Rs 1 bought the juice of = (9/378) = 1/42
∴ In Rs 504 bought the juice of = (504/42) = 12
(7) In 5 hours the motorbike can travel = 425 km
∴ In 1 hours the motorbike can travel = (425/5) = 85 km
∴ In 3.2 hours the motorbike can travel = (85 × 3.2) = 297.50 km.
(8) If the cost of 12 identical article is Rs 672
∴ Cost of 1 identical article is = Rs (672/12) = Rs 56
∴Cost of 18 identical articles is = Rs (56 × 18) = Rs 1008
(9) (i) In 5 hours the car covers = 180 km
∴ In 1 hours the car covers = (180/5) = 36 km
∴ In 3 hours the car covers = (36 × 3) = 108 km
(ii) The car covers 180 km in 5 hours
∴ The car covers 1 km in = (5/180) = (1/36) hours
∴ The car covers 54 km in = (54/36) = 1.5 hours
(10) In 3 days rained 276 cm
∴ In 1 days rained = (276/3) = 92 cm
∴ In 7 days rained = (92 × 7) = 644 cm
(11) (i) Cost of 10 kg wheat is = Rs 180
∴ Cost of 1 kg wheat = Rs (180/10) = Rs 18
∴ Cost of 18 kg wheat = Rs (18 × 18) = Rs 324
(ii) In Rs 180 get wheat = 10 kg
∴ In Rs 1 get wheat = (10/180) = 1/18 kg
∴ In Rs 432 get wheat = (432/18) = 24 kg
(12) Rohit buys 10 pens in Rs 150
∴ Rohit buys 1 pens = Rs (150/10) = Rs 15
Manoj buys 14 pens in Rs 168
∴ Manoj buys 1 pens = Rs (168/14) = Rs 12
Hence, Manoj got the pens cheaper each pen in Rs 12.