Quantitative — Linear Jump Equations
Question
A toy T jumps forward or backward. In each forward jump, it moves 5' forward whereas in each backward jump, it moves 2' backward. If in 31 jumps, T moves exactly 15' forward, then what is the difference of the number of forward and backward jumps?
Options
6
7
8
9
Explanation
Let f be the number of forward jumps and b be the number of backward jumps completed by the toy .
f + b = 31 \implies b = 31 - f \quad --- (Equation 1)
5f - 2b = 15 \quad --- (Equation 2)
5f - 2(31 - f) = 15 \implies 5f - 62 + 2f = 15 7f = 15 + 62 \implies 7f = 77 \implies f = 11 forward jumps
b = 31 - 11 = 20 backward jumps
Difference = |b - f| = |20 - 11| = 9
Answer: (d).
Question details
Year
2026
Paper
CSAT
Question
Q73
Section
Quantitative Aptitude
Sub-topic
Algebra — Linear Equations
Type
Arithmetic Problem
Difficulty
Easy
Source hint
Linear tracking — simultaneous integer variable solutions
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