4400 Higher June 2006 Paper 4 Q10
10 A mobile phone company makes a special offer.
Usually one minute of call time costs 5 cents.
For the special offer, this call time is increased by 20%.
(a) Calculate the call time which costs 5 cents during the special offer.
Give your answer in seconds. (2)
Give your answer in seconds. (2)
(b) Calculate the cost per minute for the special offer. (2)
(c) Calculate the percentage decrease in the cost per minute for the special offer. (3)
| Scheme | Marks |
|---|---|
| 60 × 20/100 or 12 sec or 1.2 min seen | M1 |
| 72 | A1 |
| (2) |
| Scheme | Marks |
|---|---|
| 5 / 72 × 60 or 5 / 1.2 | M1 |
| 4.16 to 4.17 | A1f |
| (2) |
Notes
M1: or 5/6 × 5
A1f: or 4 or 4.2 with wking (eg 5:72 = \(x\):60)
ft only if wking \(\quad\) NB!!! 80% of 5 = 4
| Scheme | Marks |
|---|---|
| “4.167”/5 × 100 \(\quad\) or \(\quad\) 5 − “4.167” | M1 |
| 100 − “83.3…” \(\quad\) or \(\quad\) “0.833..”/5 × 100 | M1 |
| 16.6% to 17% | A1 |
| (3) | |
| (7 marks) |
Notes
M1: ft M mks only if wking
A1: cao