Mirror and water images for SSC GD

Mirror and water image questions show a figure, a word, a number or a clock and ask how it would look reflected. In the exam the options are pictures, and you pick the one that is flipped correctly. This guide works without pictures, so it describes letters and clock times in words. The rules are exactly the same.

These questions come up regularly in the non-verbal part of SSC GD reasoning. They need no calculation beyond one subtraction for clocks, so with two rules and a checking habit they are among the fastest marks in the paper.

The two rules

Letters that do not change

A capital letter looks the same in a mirror if its left half matches its right half. It looks the same in water if its top half matches its bottom half. These lists are for plain capital letters, the kind used in exam options.

Words and numbers

In a mirror, two things happen. The order of letters reverses, so the last letter appears first. And each letter is flipped left to right. So a word looks the same in a mirror only if it reads the same backwards and every letter is mirror-symmetric. TOT and MOM pass; NOON fails, because N is not symmetric.

In water, the order of letters stays the same, because left and right do not swap. Each letter turns upside down. So a word looks the same in water if every letter is top–bottom symmetric. CHOICE is the classic example: C, H, O, I, C and E all survive the flip.

Clocks in a mirror

A mirror swaps the left and right halves of a clock face. A hand pointing at 3 appears to point at 9. A hand at 2 appears at 10. So the time you see is not the real time.

Mirror time = 11:60 − actual time

The 11:60 is just 12:00 written so you can subtract minutes easily (12 hours = 11 hours and 60 minutes). The formula also works backwards: if you know the mirror time, the same subtraction gives the real time.

The exception. If the time is between 11:00 and 12:59, use 23:60 instead. For example, 12:20 in a mirror is 23:60 − 12:20 = 11:40.

Solved examples

Example 1 (letters in a mirror). Which of these letters look the same in a mirror: B, H, N, U?

1. B: its bumps face right. In a mirror they face left, so it changes.
2. H: left half matches right half. Same.
3. N: the diagonal flips direction. Changes.
4. U: left and right match. Same.
5. Answer: H and U.

Example 2 (word in a mirror). Which word looks exactly the same in a mirror placed to its side: NOON, BOB, TOT, DID?

1. All four read the same backwards, so check each letter.
2. NOON has N, BOB has B, DID has D. None of these is mirror-symmetric.
3. TOT uses only T and O, both symmetric.
4. Answer: TOT.

Example 3 (word in water). Which word looks the same in water: CHOICE, WATER, MIRROR, TABLE?

1. In water, order stays and each letter turns upside down.
2. WATER has W, A, T and R, which change. MIRROR has M and R. TABLE has T, A and L.
3. CHOICE uses C, H, O, I and E, all top–bottom symmetric.
4. Answer: CHOICE.

Example 4 (clock). A clock shows 3:20. What time does its mirror image show?

1. 11:60 − 3:20.
2. Hours: 11 − 3 = 8. Minutes: 60 − 20 = 40.
3. Answer: 8:40.

Example 5 (clock, the exception). A clock shows 11:10. What time does its mirror image show?

1. The time is between 11:00 and 12:59, so use 23:60.
2. 23:60 − 11:10 = 12:50.
3. Answer: 12:50. Check: the hour hand just past 11 appears just before 1, and the minute hand at 2 appears at 10, which is 50 minutes.

Example 6 (reading backwards). In a mirror, a clock appears to show 5:25. What is the real time?

1. The formula works both ways. 11:60 − 5:25.
2. Hours: 11 − 5 = 6. Minutes: 60 − 25 = 35.
3. Answer: 6:35.

A checking method for figures

When the options are pictures:

1. Pick one clear feature: an arrow, a dot, a shaded corner.
2. Decide where it must go. For a mirror, left becomes right. For water, top becomes bottom.
3. Cross out every option where that feature is in the wrong place.
4. Check a second feature to choose between the options left.

An arrow pointing to the upper right, for example, points to the upper left in a mirror and to the lower right in water.

Common mistakes

Practice set

1. Which of these letters look the same in a mirror: A, B, T, S?
2. A clock shows 4:10. What does its mirror image show?
3. A clock shows 7:30. What does its mirror image show?
4. Which of these letters look the same in water: C, F, D, G?
5. In a mirror, an arrow pointing left will point which way?
6. A clock shows 11:45. What does its mirror image show?
7. In a mirror, a clock appears to show 2:35. What is the real time?
8. Which word looks the same in water: BOX, BAG, CAT, PEN?

Answers:

1. A and T. Both have matching left and right halves.
2. 7:50. 11:60 − 4:10.
3. 4:30. 11:60 − 7:30.
4. C and D. Both have matching top and bottom halves.
5. Right.
6. 12:15. The time is between 11:00 and 12:59, so 23:60 − 11:45 = 12:15.
7. 9:25. 11:60 − 2:35.
8. BOX. B, O and X are all top–bottom symmetric.

What to do next

• Learn the two letter lists, and write them from memory once a day for a week.
• Solve 10 clock mirror questions, including at least three between 11:00 and 12:59.
• For figure questions, always mark one feature on the rough sheet before looking at options.
• Move on to embedded figures and paper folding, the other quick non-verbal types.
• Revise calendar and clock questions, which use the same clock face.