Test Index

JAMB Mathematics 2023 Paper

© africaexams.com

Question : 26

Total: 80

Find the value of y if

402_y = 102_{\text{ten}}

4
2
5
3

Solution:

$402_y = 102_{\text{ten}}$

⇒ 4 x y $^2$ + 0 x y $^1$ + 2 x y $^0$ = 102

⇒ 4y $^2$ + 0 + 2 x 1 = 102

⇒ 4y $^2$ + 2 = 102

⇒ 4y $^2$ = 102 - 2

⇒ 4y $^2$ = 100

⇒ y $^2 = \frac{100}{4}$

⇒ y $^2$ = 25

∴ y = √25 = 5

© africaexams.com

Go to Question:

Prev Question

Next Question