Ratio

Question 1

Combined Variation

Answer 1

y varies directly with x → y = k₁x

y varies inversely with z → y = k₂/z

Combining the two: y = kx / z

Question 2

Joint Variation

Answer 2

y varies directly jointly with 2 other variables if y varies directly with each of them
→ y = kxz

y varies inversely jointly with x and z
→ y = k / xz

Question 3

Using the Concept of LCM

Answer 3

Mark’s basket contained sour candy and chocolate candy in a ratio of 4 to 3 and sour candy to sweet candy in a ratio of 5 to 2.

→ This means the number of sour candies must be a multiple of 20.