Answer:
It is after 4 explorations that the submarine's elevation would have changed by -3/2 miles
Step-by-step explanation:
From the question,
The elevation of the submarine changes by -3/8 mile after each exploration.
To determine the number of explorations it will take for the submarine's elevation to have changed by -3/2 miles, we will divide -3/2 miles by the number of miles the elevation of the submarine changes per exploration (that is, -3/8 mile),
That is,
-3/2 miles ÷ -3/8 mile
= 
= 
=
= 4
Hence, it is after 4 explorations that the submarine's elevation would have changed by -3/2 miles.
The number would be 12. If you substitute you will find that 12 is correct.
Answer:
She was wrong in her analysis because the sales discount of 25% is the discount on the original cost of the dress and not the purchasing cost of the dress as explained below:
Step-by-step explanation:
From the question:
Purchasing cost price of the dress = £30
However, this cost (£30) was after a 25% Sales Discount
It, therefore, implies that £30 is equal to 75% of the cost price
75% of the original cost price = £30
100% of the original cost price = (30 x100%)/75%
Original cost price = £40
Therefore the 25% discount / savings on the cost
= £ (40-30)
= £10
She saved £10 by buying the dress at £30 instead of the original cost of £40