Assume that the bank balance started at zero. Enter the income and outgo in chronological order: $300 - $50 - $75 + $225
Find the sum. This sum will represent the amount left in the account after the $225 deposit:
$250 - $75 + $225, or
$175 + $225 = $400 The final balance will be $400.
Step-by-step explanation:
According to this description we need a number that can be divided by 2,3 and 4 since the amount of rocks can be described by a natural number. However if a number is divided by 4 it is divided by 2 as well since 2*2=4.

If α is a natural number then 2*α is a natural number as well as the product of two natural numbers.
Which means that we need a number devided by 3 and 4.
The smallest number that fulfills this demand is 3*4=12.
Also any product of 12 with any natural number can be devided by 3, 4 and 2.
If the exercise asks for the numbers that are divided only by 2,3 and 4 these are:

A=p(1+r/100)^n
A=2500(1+4/400)^16
A=2931.45
3.7cm on the map represents 1850km in reality
3.7cm : 1850km
1cm : 1850/3.7 km
1cm : 500km
Scale statement for map is : 1cm : 500km.
That is 1cm on map represents 500km.
1cm : 500km. Recall 1km = 1000m = 100 000cm
1cm : 500* 100000cm
1cm : 50 000 000cm
1: 50 000 000.
Scale factor is 50 000 000.