So women:men=5:7
for every 5 units of women, there are 7 units of men so
there are 140 men and that equals 7 units so
140=7 units
solve for 1 unit
140/7=20
1 unit=20
women=5 units
5 times 20=100
women=100
total=women+men=100+140=240
another way would be to add up the units (5+7=12) and multiply by the amount per 1 unit
The uniforms will cost 1,360, so yes they have enough money to buy 11 uniforms.
Hope this helps.
The probability can be modeled using the following formula:

wherein X follows the density

Now for k = 3 we get:
The probability we are looking for is 0.15.
Do you have any question ?