Trini took 74 photos
Solution:
Given that Trini took some photos
The number of photos she took is a two-digit number
Let the number in unit place be x and the number in tens place be y
Then the two digit number is yx
Given that sum of digits is 11
Therefore,
x + y = 11 ---- eqn 1
The tens digit is 3 more than the ones digit
Therefore, we frame a equation as,
y = 3 + x ---- eqn 2
Solve eqn 1 and eqn 2 to get value of "x" and "y"
Substitute eqn 2 in eqn 1
x + 3 + x = 11
2x + 3 = 11
2x = 11 - 3
2x = 8
x = 4
Substitute x = 4 in eqn 2
y = 3 + 4 = 7
Thus the two digit number is 74. Thus he took 74 photos