Question
Two cyclists P and Q are at towns A and B. P sets off
toward B at (x – 8) km/h. Two hours later, Q starts toward A at (x + 8) km/h. They meet at the exact halfway point between A and B. If AB = 240 km, find P’s time to go from A to B.Solution
ATQ, Distance covered by P in 2 hours = (x – 8) × 2 = 2(x – 8) km Remaining distance = 240 – 2(x – 8) = 240 – 2x + 16 = (256 – 2x) km Time of meet after Q starts = (256 – 2x)/(2x) hours According to question, [(256 – 2x)/(2x)] × (x + 8) = 240/2 (256x + 2048 – 2x² – 16x) = 240x ⇒ –2x² + 2048 = 0 x² = 1024 x = 32 Speed of P = 32 – 8 = 24 km/h Therefore, required time = 240/24 = 10 hours
If (7a + b) : (7a - b) = 7:3, then find the value of a:b?
522 + 160% of 80 - 130 = ? X 13
140% of 75 + 152 - 160 = ?
25% of 240 + √? = (2/3) × 120
961 × 4 ÷ 31 – 15% of 180 = ? – 73
Calculate the simplified value of the given expression:
What will come in the place of question mark (?) in the given expression?
√1936 + (84 ÷ 2 × 1.5) – 35² + 18² = ?
8(3/4) + 5(1/6) – 4(3/4) = ?
{(80% of 650 + 25 × 12) – 20 × ?} = 760
36×?² + (25% of 208 +13) = 60% of 2400 + 17×18
