SHSAT Prep

SHSAT Math Question 110 — The Simple Interest Problem Most Students Miss

A step-by-step walkthrough of SHSAT Question 110 — a simple interest problem that trips up students who do the math right but stop one step too early. From the SHSAT prep team at SOMATH, Upper West Side NYC.

SHSAT Math Question 110 — The Simple Interest Problem Most Students Miss
Walkthrough from the SOMATH classroom · Watch on YouTube

Direct answer: On SHSAT Question 110, most students miss the problem because they correctly compute the interest ($17.50) but forget the question asks for the total amount after one year. You have to add the interest back to the $350 principal to get $367.50.

The question (verbatim)

Question 110. Carlos has $350 in a savings account that earns 5% simple interest each year. How much will he have in the account after 1 year, if there is no money withdrawn?

The most common wrong answer (and why)

In our SHSAT prep classes at SOMATH on 226 W 79th St, the most common wrong answer is E ($17.50). It’s not because students can’t do the percent math. It’s because they stop one step too early.

The test writers know exactly what they’re doing: the choices are engineered so that a student who makes a specific misread will see their intermediate result in the options and feel confident clicking it. That confidence is what makes this a trap question.

When students practice, they often learn formulas before they learn the habit of re-reading the question. The result: they do the computation, spot the number, and move on—exactly what the SHSAT wants them to do.

The solution, step by step

This is a two-step problem disguised as a one-step problem. Here’s the reliable procedure we teach—because on test day you want a repeatable routine, not a gut feeling.

  1. Underline what the question is actually asking for. The wording is “How much will he have in the account after 1 year?” That means the total amount in the account, not just the interest earned.
  2. Compute the interest using simple interest. The formula is Interest = Principal × Rate × Time.

Plug in the numbers:

So the interest is:

Interest = 350 × 0.05 × 1 = 17.50

Now the step students forget:

  1. Add the interest back to the principal. The account balance after 1 year is $350 + $17.50 = $367.50.

That corresponds to choice G.

The lesson: this trap repeats across the SHSAT

Simple interest shows up on essentially every SHSAT, but the point isn’t the formula. It’s the reading and the “what is the question actually asking?” skill. And this exact pattern shows up in many different disguises.

Here is the phrase we repeat in our classroom because it’s the real takeaway: the arithmetic is easy; the reading comprehension is the actual test.

Once you start looking for it, you’ll see the same structure across topics:

In other words, the “do the math right, pick the wrong final answer” mistake isn’t a one-off. It repeats across SHSAT topics because it’s a predictable human error: stopping when you see a familiar number.

How SOMATH teaches this pattern

At SOMATH, our SHSAT students don’t just do sets of percent questions; we train process. The process is what transfers when the question changes.

We teach students to create a tiny checklist for word problems:

This takes 10 seconds and saves points. It also changes how students feel during the test: instead of rushing to match an option, they’re executing a routine they’ve practiced dozens of times.

If you want to see where your child is right now—conceptually and procedurally—we offer a free 30-minute evaluation. Families receive a written diagnostic within 48 hours, with specific next steps (not vague “practice more” advice).

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We’re located at 226 W 79th St. You’ll get a 30-minute evaluation and a written diagnostic within 48 hours.

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FAQ

When should my child start SHSAT prep?

Most students start structured SHSAT prep in late 6th grade or the beginning of 7th grade, so there’s time to build skills without panic. If your child is aiming for a specialized high school and is currently behind in fractions, ratios, or percent fluency, starting earlier can reduce stress later.

How much practice is enough?

Enough practice means your child can solve a problem and explain why the steps make sense. For SHSAT math, we usually want students to master the recurring question families (fractions/percents, ratios, basic algebra, geometry, and data) and then do timed mixed sets so they learn to switch gears. Quality beats volume: repeated, corrected mistakes matter more than raw problem count.

What other question types repeat this “stop too early” pattern?

Percent word problems (discount vs final price), geometry (radius vs area), and rate problems (unit rate vs total) are the big ones. Any time the test offers an answer choice that matches an intermediate step, it’s an invitation to stop early.

Is simple interest different from compound interest on the SHSAT?

Yes. Simple interest grows linearly: you compute interest on the original principal only. Compound interest grows exponentially: you compute interest on the updated balance. On the SHSAT, when you see “simple interest,” you should immediately think “principal × rate × time,” then add it back to the principal if the question asks for the total amount.

My child is strong in math but still misses word problems. Why?

Strong computational students are often the most vulnerable to traps because they can produce an intermediate result quickly and then assume that must be the answer. Training a quick “what are they asking?” routine closes that gap.

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