SSC CGL 2025 Tier-I · 16 September 2025, Shift 2 · Quantitative Aptitude · Question 13 of 100

We transcribed this text from the pictures on a candidate's response sheet for this shift; the answer is the key SSC colour-marked on that sheet. Solution last reviewed 13 September 2026.

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SSC does not publish CGL question papers or a public answer key. From 2025 the candidate response sheet prints every question and option as a picture, so the text here is transcribed from those pictures for this shift and checked against them independently; where the layout carries meaning, the picture is shown as well. Each answer is the key SSC colour-marked on that sheet. SSC released a tentative key for challenge and later its final one, both only to candidates behind a login, and the sheet does not say which of the two it carries. The solutions are written by UnlockIAS.

The ratio of the speeds of a car and a bus is 3 : 4. If the bus covers a distance of 320 km in 4 hours, what is the speed of the car in km/h?

(a)60 km/h
(b)75 km/h
(c)80 km/h
(d)90 km/h

Answer

Why

Correct — A. Find the bus's speed, then scale it by the ratio.

Bus speed = distance ÷ time = 320 ÷ 4 = 80 km/h
Car : bus = 3 : 4, so car = 80 × 3⁄4
= 60 km/h → option (a)

Check: 60 : 80 = 3 : 4

Why the others are wrong

(b)
75 km/h — 75 km/h against the bus's 80 km/h is 15 : 16, not 3 : 4. The car's speed must be exactly three-quarters of 80.
(c)
80 km/h — 80 km/h is the bus's own speed, 320 ÷ 4. Stopping there skips the ratio step, and 80 : 80 is 1 : 1.
(d)
90 km/h — 90 km/h would make the car faster than the bus. The ratio 3 : 4 puts the car on the smaller side, so its speed is below 80 km/h.

Concept

A ratio of speeds says how the speeds compare, not what they are. One actual speed turns the ratio into numbers.

Speed = distance ÷ time gives the bus 80 km/h. The bus holds 4 parts of the ratio, so one part is 80 ÷ 4 = 20 km/h, and the car's 3 parts are 60 km/h.

The same ratio holds for distance in equal time: in the bus's 4 hours the car covers 60 × 4 = 240 km, and 240 : 320 = 3 : 4.

Key facts

Speed = distance ÷ time: 320 km in 4 hours is 80 km/h.
In equal times, distances are in the ratio of the speeds.
Over a fixed distance, times are in the inverse ratio of the speeds, so the car takes 4⁄3 of the bus's time.

Study next

Inverse proportion of time and speed over a fixed distanceRelative speed of two vehicles moving towards or away from each otherAverage speed over two legs at different speeds

Common traps

Inverting the ratio and computing 80 × 4⁄3 ≈ 106.67 km/h.
Answering the bus's speed, 80 km/h, after the first step.

A speed ratio also drives 12 Sep 2024, 12:30, Quant Q.11: with policeman to thief at 5 : 4, the 150 m lead closes by 1 part while the thief runs 4 parts, so the thief covers 600 m.

Related PYQs

No directly related past PYQ was found.

Topic: Time and distance — all 58 SSC CGL questions on it, every solved shift.