Cost of 8 pencils, 5 pens and 3 erasers is Rs 111. Cost of 9 pencils, 6 pens and 5 erasers is Rs 130. Cost of 16 pencils, 11 pens and 3 erasers is Rs 221. What is the cost price of 39 pencils, 26 pens and 13 erasers (in Rs)?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 546
8 pencils + 5 pens + 3 erasers = 111.....(1)
9 pencils + 6 pens + 5 erasers = 130 .....(2)
16 pencils + 11 pens + 3 erasers = 221.....(3)
By adding all three equations:
⇒ 33 pencils + 22 pens + 11 erasers = 462
⇒ 3 pencils + 2 pens + 1 erasers = 42 .....(4)
By multiplying 13 on both sides of equation (4)
⇒ 13 × [3 pencils + 2 pens + 1 erasers] = 42 × 13
⇒ 39 pencils + 26 pens + 13 erasers = 546