Purana and Naya are two brands of kitchen mixer-grinders available in the local market. Purana is an old brand that was introduced in 1990, while Naya was introduced in 1997. For both these brands, 20% of the mixer-grinders bought in a particular year are disposed off as junk exactly two years later. It is known that 10 Purana mixer-grinders were disposed off in 1997. The following figures show the number of Purana and Naya mixer-grinders in operation from 1995 to 2000, as at the end of the year.
Year | 1995 | 1996 | 1997 | 1998 | 1999 | 2000 |
---|---|---|---|---|---|---|
Purana | 120 | 162 | 182 | 222 | 236 | 236 |
Naya | 0 | 0 | 30 | 80 | 124 | 134 |
We are told that 20% of the mixer-grinders bought in a particular year are disposed off exactly two years later. Let’s calculate the number of Naya mixer-grinders disposed by the end of 2000.
🔹 Naya was introduced in 1997, so the first disposals happen in 1999.
Disposals:
• From 1997 purchases → disposed in 1999: 20% of 1997 Naya = 20% of 30 = 6
• From 1998 purchases → disposed in 2000: 20% of 1998 Naya = 20% of 80 = 16
Total disposed by end of 2000 = 6 + 16 = \(\boxed{22}\)
We are given the number of Naya mixer-grinders in operation at the end of each year. Let’s calculate how many were purchased in 1999.
Approach: Number in operation in 1999 = = Previous year's total (1998) + New purchases in 1999 − Disposals in 1999
From the table: • Naya in 1998 = 80 • Naya in 1999 = 124 • Disposals in 1999 = 20% of 1997 purchases = 20% of 30 = 6
So, 124 = 80 + Purchases in 1999 − 6 ⇒ Purchases in 1999 = 124 − 80 + 6 = \(\boxed{50}\)
A | B | C | D | Average |
---|---|---|---|---|
3 | 4 | 4 | ? | 4 |
3 | ? | 5 | ? | 4 |
? | 3 | 3 | ? | 4 |
? | ? | ? | ? | 4.25 |
4 | 4 | 4 | 4.25 |