[신나는 공부]Let's Think! 영어사고력 문제

■ 응모 문제 ■

There is a chain made of three interlinked rings. Say there are 5 such chains. We want to cut some of the rings so that we can link all five chains. What is the minimum number of rings that we should cut? (Here, we cannot connect three rings to another ring.)

Tip!

interlinked → 서로 연결된
연결된 고리를 끊어 다른 체인과 잇는 문제입니다. 고리를 끊는 횟수를 최소화하려면 몇 개를 끊어야 할까요?

■ 도전! 하나 ■

Let’s see how observant you are! Which of the following solids is the same as the one given below?

Tip!

observant → 관찰력이 있는
solid → 입체
단위 정육면체가 붙어 있는 방향과 숫자에 주목하세요!

■ 도전! 둘 ■

Once upon a time, a tradesman turned all of his fortune into gold. He decided to leave it to only one of his sons who was the smartest. For this aim, he prepared three boxes among which only one contained his gold. The three sons came in and saw the following statements written on the surface of the three boxes, A, B, C.

(Box A) There is no gold in box C.

(Box B) There is no gold in this box.

(Box C) There is gold in this box.

To the perplexed sons, the father gave a hint: among the statements, one at most is true. It is said that the smartest son figured out the box with gold; he built the greatest business in the land out of the fortune. What should the box have been?

Tip!

tradesman → 상인
all of one's fortune → 전 재산
for this aim → 이를 위해
one at most is true → 기껏해야 하나만 진실이다.
he built ∼ business out of the fortune → 그는 그 재산을 바탕으로 사업을 일궜다
What should the box have been? → 그 상자는 무엇이어야 했을까? (should는 확실한 추측을 나타내는 과거형임에 주목)

■ 도전! 셋 ■

Look at the way a group of 5 numbers are bound together by a cross-shaped area. Which of the following numbers cannot be the sum of 5 such numbers?

① 50 ② 75 ③ 110 ④ 120 ⑤ 155

Tip!

bound together → 함께 묶여 있는

cross-shaped → 십자 모양의
sum → 합

■ 도전! 넷 ■

It takes two hours and half from Seoul to Pusan, and also from Pusan to Seoul, by express train. At Pusan and Seoul, respectively, the first express train leaves at 6 am., and after that there is train at every hour. Say a train left Seoul at 9 am. How many times would that train meet trains coming from Pusan?

Tip!

express train → 급행열차

There is train at every hour. → 한 시간마다 기차가 있다. 이때 hour는 단수로 쓰임.
각 열차의 출발 시각과 도착 시각을 생각해봅시다.
두 열차가 서로 만나는 시각도 생각해야 할까요?

■ 도전! 다섯 ■

Say you make four-digit numbers with the four cards below. What is the sum of the second largest and the second smallest among such numbers?

Tip!

digit은 ‘자릿수’라는 뜻으로, four-digit number는 네 자릿수를 의미.
‘Each digit is smaller than 5’라고 할 때는 각각의 자

릿수가 모두 5보다 작다는 의미.

★ CMS 홈페이지 ‘Let’s think’ 영어듣기 문제 정답자 1명을 뽑아 닌텐도DS를 드립니다.

☞ 응모문제의 정답을 맞힌 학생 중 5명을 선정해 5만 원 상당의 문화상품권을 드립니다. CMS 홈페이지(www.cmsonlin.co.kr) 코너에서 응모방법과 원어민동영상 강의를 보실 수 있습니다.