Table shows the average speed (km/h) of five trains A to E from Monday to Saturday. Dashes are missing values to be calculated if required.

Train	Mon	Tue	Wed	Thu	Fri	Sat
A	72	80	—	64	54	—
B	88	—	80	—	72	90
C	54	70	72	—	64	60
D	—	120	95	—	90	110
E	72	80	84	75	—	—

For train E, if the ratio of the average speed on Saturday to that on Friday is 5:3, then the average speed on Saturday is what percent more than that on Friday?

A66 and 2 by 3 percent ✓ Correct

B33 and 2 by 3 percent

C55 and 2 by 3 percent

D77 and 2 by 3 percent

Correct answer: (A) 66 and 2 by 3 percent

Explanation

The Saturday speed is 66 and 2 by 3 percent more, so the answer is 66 and 2 by 3 percent.

Let the Saturday speed be 5x and the Friday speed be 3x, from the ratio 5 to 3.

The excess of Saturday over Friday is 5x minus 3x, which is 2x.

As a percentage of the Friday speed this is 2x over 3x times 100.

The x values cancel, leaving 2 over 3 times 100.

That is 200 over 3, which is 66 and 2 by 3.

So the Saturday speed is 66 and 2 by 3 percent more than the Friday speed.

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Train	Mon	Tue	Wed	Thu	Fri	Sat
A	72	80	—	64	54	—
B	88	—	80	—	72	90
C	54	70	72	—	64	60
D	—	120	95	—	90	110
E	72	80	84	75	—	—

Train	Mon	Tue	Wed	Thu	Fri	Sat
A	72	80	—	64	54	—
B	88	—	80	—	72	90
C	54	70	72	—	64	60
D	—	120	95	—	90	110
E	72	80	84	75	—	—

Train	Mon	Tue	Wed	Thu	Fri	Sat
A	72	80	—	64	54	—
B	88	—	80	—	72	90
C	54	70	72	—	64	60
D	—	120	95	—	90	110
E	72	80	84	75	—	—