Question

Kalsom answers 25 questions in math tests. He scored 81% to 93%. Calculate all possible number of questions successfully answered by Kalsom. How to solve it.​

Answer 1

Answer:

21 and 22

Step-by-step explanation:

Let's work backward from that 81%:  x/25 = 0.81 yields x = 20.25.  Nominally, 20.25 / 25 = 0.81, but x must be an integer.  Let's round 20.25 off to 20.

Thus, if Kalsom got 81%, it was a result of his having done 20 questions correctly.

81% corresponds to 20 questions correct;

82% to 20.5 questions correct, or, rounding up, to 21 questions correct;

83% to 20.75, or 21;

84% to 21 questions correct; this is the only result that makes sense (whole number of questions answered correctly)

85% to 21.25;

86% to 21.5;

87% to 21.75;

88% to 22 questions correct (this makes sense, unlike the last three)

89% to 22.25;

90% to 22.5;

91% to 22.75;

Assuming that the number of questions correct MUST be integer, then the possible number correct are 21 and 22, corresponding to 84% and 88% respectively.