A lift has the capacity of 18 adults or 30 children. How many children can board the lift with 12 adults?

Correct Option (B)

The lift's capacity is equivalent to 18 adults or 30 children. This establishes a conversion ratio between adults and children for the lift's capacity.

The capacity equivalent of one adult can be determined as follows:

• 18 adults = 30 children
• 1 adult = $\frac{30}{18}$ children = $\frac{5}{3}$ children

If 12 adults have already boarded the lift, the remaining capacity in terms of adults is:

• Remaining capacity = Total adult capacity - Adults already boarded
• Remaining capacity = 18 adults - 12 adults = 6 adults

To find out how many children can board with this remaining capacity, convert the 6 adults into their child equivalent:

• Number of children = 6 adults $\times$ $\frac{5}{3}$ children/adult = 10 children

Therefore, 10 children can board the lift with 12 adults.

Incorrect Options:

The other options are incorrect as they do not align with the established capacity ratio and the calculation of remaining capacity.

• Option A (6): This number represents the remaining adult capacity, not the equivalent number of children.

• Option C (12): This is the number of adults already in the lift, not the number of children that can additionally board.

• Option D (15): This value does not correspond to the correct conversion of the remaining adult capacity (6 adults) into children based on the given lift capacity.