7 dollars and 30 cents becuse 4 wuarters equals 1 dollar plus the 5 other equals 6 dollars and then you have 2 quarters left which equals 6 dollars and 50 cents plus the 8 dimes/80 cents and 6 dollars and 50 cents plus 80 cents equals 7 dollars and 30 cents
Hello,
let's assume j the john's age, m the mary's age.
<span>"John is twice as old as mary"==>j=2*m
</span>
<span>"the sum of their ages is 21" ==>j+m=21
==>2*m+m=21
==>3m=21
==>m=7
and j=21-7=14
</span>
Answer:
Ren was 27.5 meters away from her family.
Step-by-step explanation:
Ren Qian was at a height of 10 meters to the ground. Let the distance from her vertical point on the ground to her family (i.e the ground distance) be represented by x.
But the angle of depression is measured with respect to the horizontal plane, so;
the vertical angle =
- 20°
= 
Applying the appropriate trigonometric function, we have;
Tan θ = 
Tan
= 
⇒ x = 10 x Tan 
= 10 x 2.7475
= 27.475
x = 27.5 meters
Ren was 27.5 meters away from her family.