Carcass wrote:
Jhon bought an ordinary mobile and a cover for $ 2000. Prince bought a smart phone and the same cover for $ 2000 more than what Jhon had paid. The price of the cover was one tenth of the combined cost of 2 mobiles. what is the cost of the ordinary mobile?
A) $1000
B) $1200
C) $1500
D) $1600
E)$1800
Kudos for the right answer and explanation
Question part of the project GRE Quantitative Reasoning Daily Challenge - (2021) EDITIONGRE - Math BookLet M = cost of ordinary mobile
Let C = cost of the cover
Let S = cost of smart mobile
Jhon bought an ordinary mobile and a cover for $ 2000We get:
M + C = 2000Prince bought a smart phone and the same cover for $ 2000 more than what Jhon had paid. We get:
S + C = 4000 The price of the cover was one tenth of the combined cost of 2 mobiles. what is the cost of the ordinary mobile?We get: C = 1/10(M + S)
Multiply both sides by 10 to get:
10C = M + SLots of options from here. Here's one approach:
Take:
M + C = 2000S + C = 4000ADD them to get:
M + S + 2C = 6000Replace
M + S with
10C to get:
10C + 2C = 6000Simplify: 12C = 6000
Solve: C = 6000/12 = 500
We already know that
M + C = 2000Since C = 500, we can see that M = 1500
Answer: C
Cheers,
Brent