Question 53

x = 1.5

To solve for x in the proportion 120:x::40:0.5, we can cross-multiply. This gives us the equation 120 * 0.5 = 40 * x, leading us to determine that x equals 1.5.

A) 16

This option is incorrect because if we substitute x with 16 in the proportion, the cross-multiplication would yield 120 * 0.5, which equals 60, while 40 * 16 equals 640. These two results are not equal.

B) 0.167

This choice is also incorrect. If x were 0.167, substituting it into the proportion would result in 40 * 0.167, which equals 6.68. This does not match the result of 120 * 0.5, which is 60.

C) 60

This option is incorrect as well. Substituting 60 for x would give us 40 * 60, which equals 2400. This does not equal the product of 120 and 0.5, which is only 60.

D) 1.5

This is the correct answer. By substituting x with 1.5, we find that 40 * 1.5 equals 60, which matches the result of 120 * 0.5, confirming the proportion is valid.

Conclusion

The correct answer is 1.5 because it maintains the equality of the proportion when cross-multiplied. All other options fail to satisfy the equation derived from the proportion, demonstrating their incorrectness in the context of the problem.