In this sentence-correction question on idiomatic usage, choose which phrase, if any, should replace the highlighted part "a ballparks worth of figures of how much this event is going to cost us" in the sentence ""I need you to give me a ballparks worth of figures of how much this event is going to cost us in the next two months.""

Introduction / Context:
This question tests your knowledge of idiomatic business English, particularly the phrase "ballpark figure", which means an approximate estimate. The original sentence is: ""I need you to give me a ballparks worth of figures of how much this event is going to cost us in the next two months."" The highlighted part is "a ballparks worth of figures of how much this event is going to cost us". You must decide which suggested alternative phrase best expresses this idea correctly and naturally, or whether no correction is needed.

Given Data / Assumptions:

• Original phrase: "a ballparks worth of figures of how much this event is going to cost us".
• Option (i): give me a ballpark figure of how much this event is going to cost.
• Option (ii): give me the biggest ballpark of your figure, how much this event is going to cost.
• Option (iii): give me a ballpark figure of how much this event is coming to cost.
• The speaker wants a rough estimate of the cost of the event over the next two months.

Concept / Approach:
The standard idiomatic expression is "ballpark figure", not "ballparks worth of figures". The noun "ballpark" is used attributively to modify "figure". The correct structure is "give me a ballpark figure of how much this event is going to cost us". Among the options, only option (i) uses this standard phrase with correct grammar and natural tense. Option (iii) is not as natural because "is coming to cost" is an awkward tense choice in this context, and option (ii) is clearly incorrect and unidiomatic.

Step-by-Step Solution:
Step 1: Recognize that "a ballparks worth of figures" is not an idiomatic expression in English. Step 2: Recall the correct phrase "a ballpark figure", meaning an approximate amount. Step 3: Examine option (i): "give me a ballpark figure of how much this event is going to cost" – this is grammatical and uses the idiom correctly. Step 4: Examine option (ii): "give me the biggest ballpark of your figure, how much this event is going to cost" – this is grammatically confused and does not reflect correct usage. Step 5: Examine option (iii): "give me a ballpark figure of how much this event is coming to cost" – "is coming to cost" is unnecessarily awkward; "is going to cost" is the natural future expression. Step 6: Choose option (i) as the best, idiomatic replacement that corrects both wording and structure.

Verification / Alternative check:
Insert option (i) into the sentence: ""I need you to give me a ballpark figure of how much this event is going to cost us in the next two months."" This is fluent and natural business English. It clearly communicates that the speaker wants an approximate estimate, not an exact calculation. The phrase "is going to cost us in the next two months" correctly expresses a near-future financial impact. Option (iii) would slightly change this to "is coming to cost", which is not a standard usage in such contexts.

Why Other Options Are Wrong:
The original phrase uses "a ballparks worth of figures", which incorrectly pluralises "ballpark" and adds "worth of figures", making the idiom unrecognisable. Option (ii) "the biggest ballpark of your figure" is not a recognised expression and is grammatically awkward, adding unnecessary confusion. Option (iii) "a ballpark figure of how much this event is coming to cost" is close but uses an unnatural tense; examiners will prefer the more standard "is going to cost".

Common Pitfalls:
Students sometimes invent their own variants of idioms by adding extra words like "worth of" or changing the plurality, which makes the expression sound strange. Another mistake is to overcomplicate the tense in the verb phrase, for example "is coming to cost" instead of the simple and widely accepted "is going to cost". In sentence-improvement problems, always aim for the version that matches standard written English and commonly used business or conversational phrases.

Final Answer:
The correct replacement is Only i, so the sentence should use the phrase "give me a ballpark figure of how much this event is going to cost us in the next two months".