She saves 10 per week.......after 4 weeks, she had 90
so if she started with nothing, after 4 weeks she would have 40.....but for her to have 90, she would have had to have started with (90 - 40) = 50.
Think about it....she starts with 50....and then saves 10 for 4 weeks giving her 40......and now she has 40 + 50 = 90
so ur answer is : Roberta had $ 50 before she started to save money each week
Answer:
1503 quarters
Step-by-step explanation:
There are 4 quarters in 1 dollar, so we multiply this number by 4.
375.75 * 4 = 1503
Speed of the east bound cyclist is 12 mph and the speed of west bound cyclist is 15 mph.
<u>Solution:</u>
Let us assume that x is speed of slower eastbound cyclist
So, x+3 will be the speed of faster westbound cyclist
We know that distance is the product of speed and time. That is,

West-bound DATA:
Rate of speed = x+3 mph ; Time = 6 hrs ; distance = 6(x+3) = 6x+18 miles
East-bound DATA:
Rate of speed = x mph ; time = 6 hrs. ; distance = 6x miles
On solving,
Distance apart = 162



So, the rate of speed of the east bound cyclist is 12 mph and the rate of speed of the west bound cyclist will be 
Answer:
sin b = 0.8
Step-by-step explanation:
Since a and b are complementary angles , then
sin b = cos a = 0.8