the amount of gasoline used by a car varies jointly as the distance travelled and the square root of the speed. Suppose a car used 25 liters on a 100 km trip at 100kph, about how many liters will it use on 1000 km trip at 64 kph?

200 litres

Step-by-step explanation:

let g be gasoline used, d the distance travelled and s the speed, then the equation relating the quantities is

g = kd ← k is the constant of variation

To find k use g = 25, d = 100 and s = 100, then

25 = k × 100 × = k × 100 × 10 = 1000k ( divide both sides by 1000 )

0.025 = k

g = 0.025d ← equation of variation

When d = 1000 and s = 64, then

g = 0.025 × 1000 × = 0.025 × 1000 × 8 = 200

7! = 7×6×5×4×3×2

3! = 3× 2

as 7! is multiple of 3! because 7! contains 3! that is 3× 2 as factor

so 7! /(3! ) = 7× 6× 5× 4

= 42 × 20

= 840

its b) 840✌✌✌

dhruv⭐