Let the nos.be x and y
x - unit's digit
y-ten's digit
x+y=5 (equation no.1)
10x+y=3y+2 (equation no. 2)
simplified: 10x-2y=2 (equation no. 2)
multiply 1st equation by 2 : 2x+2y=10 (equation no. 3)
add equations 3 and 2 : 12x=12 [ as the y gets cancelled : -2y+ (+2y) ]
divide both sides by 12 : X=1
from our 1st equation : Y=5-1
y=4
the 2 digit no. Is 41.
you can check your answer :
Reversed no. Is 14, and it does exceed 3 time the original tens digit ( 3 * 4 =12) by 2
x - unit's digit
y-ten's digit
x+y=5 (equation no.1)
10x+y=3y+2 (equation no. 2)
simplified: 10x-2y=2 (equation no. 2)
multiply 1st equation by 2 : 2x+2y=10 (equation no. 3)
add equations 3 and 2 : 12x=12 [ as the y gets cancelled : -2y+ (+2y) ]
divide both sides by 12 : X=1
from our 1st equation : Y=5-1
y=4
the 2 digit no. Is 41.
you can check your answer :
Reversed no. Is 14, and it does exceed 3 time the original tens digit ( 3 * 4 =12) by 2