Final answer:
Expression (c) '-10/5' cannot be used to find the cave explorer's depth after 5 minutes, as it incorrectly applies division instead of multiplication of the descent rate by the number of minutes.
Step-by-step explanation:
A cave explorer descends at a rate of 10m/min. To find her depth after 5 minutes, you would need an expression that multiplies her descent rate by the number of minutes. The correct expressions as provided are:
- (a) (-10) + (-10) + (-10) + (-10) + (-10)
- (b) -10(5)
- (d) -10 - 10 - 10 - 10 - 10
These all correctly calculate a depth of 50m after 5 minutes. However, expression (c) -10/5, incorrectly calculates the depth because it divides the rate by the time instead of multiplying. Dividing would imply finding the rate per unit of time, which is not the aim here. Therefore, expression (c) cannot be used to find her depth after 5 minutes.