Question
A motorcyclist travels the first
half of his trip at a speed of 4x km/h and the second half at a speed of 4x – 10 km/h. If his average speed for the full journey is 44 km/h, find the value of x. [x > 5]Solution
According to the question, (2 × 4x × (4x – 10)) / (4x + 4x – 10) = 44 ⇒ x(4x – 10) / (8x – 10) = 22 ⇒ 22(8x – 10) = x(4x – 10) ⇒ 176x – 220 = 4x² – 10x ⇒ 4x² – 186x + 220 = 0 ⇒ 2x(2x – 93) – 10(2x – 11) = 0 ⇒ (2x – 10)(2x – 11) = 0 ⇒ x = 11 or x = 5 ∴ x = 11
More Time and distance Questions
154 × 7 + 480 × 5 =?% of 6956
- What will come in place of the question mark (?) in the following questions?
100−[20+4×5]=? [4(2/3) + 5(1/6)] × 45% of 240 = ?
30 of 20 - 40 + 182 - 23 × ? = 83
Determine the simplified value of following expression:
0.998 + 0.882 + 0.12
What will come in the place of question mark (?) in the given expression?
[{(24) 2 ÷ (6) 2 } ÷ 8]4 = ? ÷ 5
540240 ÷ 24 ÷ 25 =?
√1369 + √1024 + √841 =(?)2 − 46
14 × 11 + 25 – ? = 21% of 300
33 × 5 - ?% of 250 = 62 - 6
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