The cost of four cycle tyres and three tubes is Rs720, whereas the cost of three cycle tyres and four tubes is Rs 610. What is the cost of a tube?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. Rs 40.
4 cycle tyres + 3 tubes = 720 ---------- (1)
3 cycle tyres + 4 tubes = 610 ------------ (2)
Add equations 1 and 2,
7 cycle tyres + 7 tubes = 1330
7 ( cycle tyres + tubes ) = 1330
cycle tyres + tubes = 1330 ÷ 7 = 190
cycle tyres = 190 - tubes
Put the value of cycle tyres in Equation (1)
4 (190 - tubes) + 3 tubes = 720
760 -4 tubes + 3 tubes = 720
760 - tubes = 720
tubes = 760 - 720 = 40
Thus, the cost of a tube = Rs 40