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JAMB Mathematics Past Questions & Answers - Page 77

381.

Find the number of ways that the letters of the word EXCELLENCE be arranged

$\frac{10!}{2!2!2!}$

$\frac{10!}{4!2!}$

$\frac{10!}{4!2!2!}$

$\frac{10!}{2!2!}$

View answer & explanation

Correct answer is C

EXCELLENCE

It is a ten letter word = 10!

Since we have repeating letters, we have to divide to remove the duplicates accordingly. There are 4 Es, 2 Cs, 2 Ls

∴ there are
$\frac{10!}{4!2!2!}$ ways to arrange

382.

A car dealer bought a second-hand car for 250,000 and spent N 70,000 refurbishing it. He then sold the car for N400,000. What is the percentage gain?

60%

32%

25%

20%

View answer & explanation

Correct answer is C

Total Cost Price = N(250,000 + 70,000)

= N 320,000

Selling Price = N 400,000(Given)

Gain = Selling Price - Cost Price

= 400,000 - 320,000

= 80,000

% gain = $\frac{\text{Gain}}{\text{Cost Price}}$ × 100

= $\frac{80,000}{320,000}$ × 100

Gain % = 25%

383.

Divide 4x3 - 3x + 1 by 2x - 1

2x² -x + 1

2x² - x -1

2x² + x + 1

2x² + x -1

View answer & explanation

Correct answer is D

by method of long division, we get the answer.

384.

In the figure, find x

40^o

55^o

50^o

60^o

View answer & explanation

Correct answer is A

Sum of angle at a point = 360^o

2x + 3x + 4x = 360

9x = 360

x = $\frac{360}{9}$

x = 40^o

385.

A man covered a distance of 50 miles on his first trip, on a later trip he traveled 300 miles while going 3 times as fast. His new time compared with the old distance was?

three times as much

the same

twice as much

half as much

View answer & explanation

Correct answer is C

Let the speed of the 1st trip be x miles/hr

and the speed of the 2nd trip be 3x miles/hr

Speed = distance/time

∴ Time taken to cover a distance of 50 miles on the 1st trip

= $\frac{50}{xhr}$

time taken to cover a distance of 300 miles on the next trip

= $\frac{300}{3xhr}$

= $\frac{100}{xhr}$

∴the new time compared with the old time is twice as much