(a) Number of gold coins Princess Elsa got = 100 Number of gold coins Princess Anna got = 100 Princess Elsa used the coins to start the business and doubled her coins. So, the number of coins Princess Elsa has = 2 × 100 Princess Anna bought jewellery and has only half of the coins left. So, the number of coins Princess Anna has = \(\frac{100}{2}\) Therefore, the total number of gold coins Princess Elsa and Princess Anna have together = 2 × 100 + \(\frac{100}{2}\) Thus, the expression describing the above situation is 2 × 100 + \(\frac{100}{2}\) Terms: 2 × 100, \(\frac{100}{2}\) Now, 2 × 100 + \(\frac{100}{2}\) = 200 + 50 = 250 (b) (i) Metro train ticket for an adult = ₹ 40 So, the metro train ticket for four adults = 4 × 40 Metro train ticket for a child = ₹ 20 So, the metro train ticket for three children = 3 × 20 Therefore, the expression describing the total cost of tickets for four adults and three children is 4 × 40 + 3 × 20 Terms: 4 × 40, 3 × 20 Now, 4 × 40 + 3 × 20 = 160 + 60 = 220 (ii) Metro train ticket for an adult = ₹ 40 So, the metro train ticket for a group of three adults = 3 × 40 Therefore, the expression describing the total cost of tickets for the two groups having three adults each is 2 × (3 × 40). Terms: 2 × (3 × 40) Now, 2 × (3 × 40) = 2 × 120 = 240 (c) By observing the given picture, the total height of the window = number of gaps × 5 cm + number of grills × 2 cm + number of borders × 3 cm = 7 × 5 + 6 × 2 + 2 × 3 Terms: 7 × 5, 6 × 2, 2 × 3 Now, 7 × 5 + 6 × 2 + 2 × 3 = 35 + 12 + 6 = 47 + 6 = 53 Tinker the Terms I NCERT In-Text Questions (Pages 36-37) Some expressions are given in the following three columns. In each column, one or more terms are changed from the first expression. Go through the example (in the first column) and fill in the blanks, doing as little computation as possible. Solution: Figure it Out (Pages 37-38)